Hello everyone, I thought I’d pop by and let you know that I’ll be selling my jewellery at the Kopparberg rock and jewellery show this weekend, the 28th and 29th of July. And I thought it would be fun to show you what I’m bringing, sort of like a pre-peek so you know what to snag up when you’re at my booth 😉
I also wanted to give you a little heads up that I might have some sort of special pricing happening during the event. And, I would absolutely love to meet you so if you happen to be nearby or plan on going, please do stop by my booth and say h e l l o.
Lots of jewels to choose from
So first up is of course a l l of my birthstone jewellery. Not only the necklaces I sell in my Etsy shop, but also earrings and bracelets that for some reason take forever to get online. I only have one of each of the earrings and bracelets in each metal (sterling silver and 14k gold fill) but I have a couple of more of every necklace in each metal so you don’t have to worry on any FOMO happening.
Dainty, delicate and sparkly. You can never go wrong with a birthstone jewellery set featuring genuine gemstones.
Runner up for what I’m bringing is my beloved BERRY jewellery! These necklaces and earrings are inspired by the wild berries growing aplenty in our beautiful Swedish nature and come in lingonberry, blueberry and cloudberry. I took real care on deciding what mineral too choose for each berry. I wanted them to look as close to the real berry as possible and I’m really pleased with my choices. Dumortierite for blueberry, bamboo coral for lingonberry and carnelian for cloudberry.
Swedish berries transformed into necklaces and earrings. A must for any berry lover out there!
Another collection I’m bringing with me is the Spring Collection I made earlier this year. This collection consists of 5 necklaces in colours of green and blue, inspired by the sky and all of the greens that starts popping out in springtime. The necklaces feature peridot, prehnite, amazonite, aquamarine and blue chalcedony, all of which in different designs. There is only one of each left so if you fancy one you better grab it before the show!
Spring Collection 2018 featuring (from top left to bottom right) amazonite, peridot, prehnite + aquamarine, prehnite and blue chalcedony + peridot.
I’m also bringing my silk + stone necklaces. These necklaces are hand knotted by yours truly using silk thread in a fun colour and water clear, smooth, quartz oval beads. Each necklace takes approximately 2.5 hours from start to finish so they are a real labour of love. I can also testify that they are baby proof having survived my little son’s curious hands pulling and tugging on the first one I made for myself for several months while breast feeding him.
Silk + stone. Hand knotted using silk thread and quartz beads. It will look like water drops held together by string around your neck.
I’m also bringing some new designs, such as my included quartz pieces which consists of tourmalinated quartz and lepidocrocite quartz in the form of simple necklaces and earrings. These pieces are so cool and unique and none of them will be quite like the other due to the irregular patterns made by the inclusions during crystal growth. So if you’re looking for something completely one of a kind, these are it!
Tourmalinated quartz and lepidocrocite quartz. Two of nature’s wonders transformed into dainty jewellery pieces. Truly one of a kind.
Another new design I’m bringing is my gemstone circle earrings comprising of tiny gemstone beads threaded on to a thin piece of wire which is then looped and wire wrapped close. The earrings feature raw diamonds, lapis lazuli, pyrite, garnet, amethyst and turquoise and come in either sterling silver or 14k gold fill. The perfect little earrings to wear everyday.
Gemstone circle earrings featuring genuine gemstones in either 14k gold fill or sterling silver. Some edgy, some boho and some luxurious. Which pair would you choose?
Last but not least (I think) I’m bringing my handcrafted fine silver stacking rings. Available in three simple and minimalistic designs they are perfect for stacking and for wearing every day. Especially since the fine silver doesn’t tarnish as easily as sterling silver does. Put them on and never take them off!
Fine silver stacking rings in three designs. Comfortable, minimal and perfect for stacking.
Ok, phew, I think that was it. It seems I’ll be bringing a lot of jewels with me and hopefully my inventory will be a little lighter at the end of the show!
Show weekend treat
I have decided to sell all of the pieces I’m bringing (minus the stacking rings) at 20% off during the show! Now if that’s not an incentive to stop by I don’t know what is.
One of the reasons for doing so is just to give you guys attending the event a treat! The second reason is because I’m planning on retiring some of my old designs to make way for some new pieces I’m super excited about. But to have the time I need to stop making some old designs, to narrow down what I’m making in order to focus on what’s ahead for this business of mine. As for now, I haven’t exactly decided on which designs (or how many) to retire, but I’ll let you know beforehand so you’ll have time to snag something up before they are gone forever.
That’s it for today and I hope I’ll see you at the show!
We’re halfway through the year folks, when did that even happen?! The first half has been so much fun but it’s been speeding by for me and I feel like it really needs to slow down. So much to do / see / enjoy and so little time.
Anyway, let’s steer the focus back to the birthstone for this very summery month – the ruby. You July babes sure are lucky to have this fabulous gemstone as your birthstone!
Ruby jewellery set, the perfect set for a July born babe who likes a touch of feminine pink. All pieces made by Linda Sääv.
The feminine ruby
Rubies for me are the embodiment of femininity in a gemstone. Their hot pink to blood red colour is divine and are loved by women of all ages. Even someone who might not be that in to pink will still get intrigued by a ruby.
I mean if your jaw doesn’t drop from the sight of the ruby pictured below, you need to get your eyes checked!
Hot pink and glowing little ruby wrapped in flattering 14k rose gold fill wire. Made by Linda Sääv.
Ruby science
The ruby is a pink to red variety of the mineral corundum (aluminium oxide, Al2O3) and is a sibling to the other corundum colour varieties named sapphires. In fact, all other gem-quality corundum stones not having a shade of pink or red is called sapphires (read on for the pink sapphire versus ruby debate).
A completely pure corundum is colourless, so rubies get their colour from trace amounts of chromium in the crystal lattice. The more chromium, the stronger the red colour. The chromium can also cause fluorescence, which adds to the glow and intensity of the red colour when viewed under ultraviolet light – even from the ultraviolet light in sunlight.
Top left: colourless corundum crystal. Bottom left: irregularly shaped glowing pink ruby with a hint of orange. Right: raw ruby, loose and in host rock with a hint of purple. The faceted ruby is more red with a hint of pink.
Iron can also be present in the chemical makeup of a ruby. Iron on the other hand can make the rubies darker and less intense in colour. Higher iron content can also mask the red fluorescence.
50 shades of red
Although rubies are defined to be red, they may exhibit a range of secondary hues, including orange, purple, violet and pink (as already seen in the previous photo). Of the three, purple is preferred because it reinforces the red, making it appear richer. However, too much purple and the ruby moves down the quality scale.
50 shades of red. Nah, just kidding, sort of. Even though it might not look like it, all rubies are defined to be red in hue. The pink or purple colouration you see is only caused by their secondary hues.
The ruby hex
Rubies (as all corundum varieties) are part of the trigonal crystal system and most often occur naturally as terminated tabular hexagonal prisms. Imagine two stretched six-sided pyramids attached at their base and you have a rough idea of how a ruby crystal looks like.
Top left: raw ruby crystal showing off its hexagonal shape, it’s also showing off that it’s part of the trigonal system with the triangle on its top. Right: a raw ruby with a faint hexagonal shape. Bottom left: a collection of ruby crystals and clusters (and one blue sapphire).
Rubies are naturally very hard with a hardness of 9 on the Mohs scale of mineral hardness. Only moissanite and diamond are harder, with diamond having a hardness of 10 and moissanite falling somewhere in between corundum and diamond.
Naturally imperfect
When it comes to imperfections, all natural rubies have them. Imperfections include colour impurities and inclusions of rutile needles known as “silk”. It’s the rutile inclusions that make distinguishing natural rubies from synthetics or simulants possible.
Left: rutile needles (golden) on hematite (metallic). Top right: microscope image of a criss cross pattern made by rutile needles in a ruby. Bottom right: Close up of thin rutile needles making the same but faint criss cross pattern seen above.
The rutile inclusions can sometimes cause an optical phenomenon called asterism. An asterism or “star” is a three-point or six-point surface effect that occur when light is reflected off the structurally oriented rutile needle inclusions of the stone in a certain way. These rubies are usually cut into cabochons to properly display the effect. Similarly, rubies can also show chatoyancy, also called the “cat’s eye” effect. In this case, the rutile needle inclusions are actually increasing the value of the ruby.
Two cabochon cut star rubies clearly showing the six-pointed surface effect caused by the silk within.
These days, almost all rubies are treated in some form, with heat treatment being the most common practice. Heat treatment of a ruby improves the colour, removes any purple tinge as well as “silk” which also improves the clarity.
Another treatment is lead glass filling, a treatment where any fractures inside the ruby is filled with lead glass, a treatment that dramatically improves the transparency of the stone.
Untreated rough rubies (left) versus heat treated rough rubies (right).
Ruby vs. pink sapphire
The distinction between ruby and pink sapphire is often made by looking at the colour saturation of the stone. If the saturation isn’t high enough it will be called a pink sapphire and subsequently, if the saturation is above a specific threshold it will be called a ruby. Furthermore, one can argue that for a corundum to be called a ruby, red must be the dominant hue.
However, often, the identification of the dominant hue is difficult and can be debated – it’s not clear and it really is just a matter of personal perception.
Historically though, the word ruby referred to shades of red, which technically included pink.
Four different corundums having the same hue (red), but showing a variation in saturation and tone. Most gem dealers would classify number 3 and 4 as rubies, whereas number 1 would be classified as a pink sapphire. Number 2 walks the line, it’s a ruby to some, while a pink sapphire to others.
The queen of gems
Ruby is the most valuable variety of the corundum mineral species and rubies can in fact command the highest per-carat price of any coloured gemstone.
The quality of a ruby is determined by the same principles as other precious gemstones: colour, cut, clarity and carat weight – all of which affects its value.
For rubies, colour is the most important quality factor. The finest ruby has a pure, vibrant red to slightly purplish red colour – called “pigeon’s blood” rubies. After colour follows clarity: a clear stone will naturally be more valuable. However, a ruby without any needle-like rutile inclusions may indicate that the stone has been treated, which lowers its value.
Rubies in the wild
Rubies are most often found in marble. The most renowned rubies, like those from Myanmar, the Himalayas and northern Vietnam, typically form in marble.
Here they’re found in layers that are distributed irregularly within the surrounding marble. The marble is formed from existing limestone deposits during metamorphic (rock-altering) processes.
Marble is a type of rock with low iron content, which means rubies formed in marble are more likely to have an intense red colour due to the lack of iron.
Rubies in marble showing off their more vivid colouration.
Rubies can also be found in basalt rocks. Basalt has high iron content which means that rubies originating in these rocks can have higher iron content as well. And as you’ve already read, the addition of iron can cause the rubies to be darker and less intense in colour (see picture below), as well as mask the red fluorescence, eliminating that extra glow of red colour seen in rubies originating from marbles.
Another type of ruby is found in amphibolite and the most renowned ones originate from Mozambique. These rubies are quite fascinating due to their range in iron content, from as high as rubies found in basalts to as low as rubies found in marbles. This of course causes a wide range of colours for rubies mined in this area.
Top left: rubies in amphibolite. Right: rubies with high iron content.Bottom left: rubies with low iron content.
So which ruby is your favourite? The more red ones or the more pink ones? I for one is a sucker for those hot pink fuchsia coloured ones!
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I hope this blog post was interesting and fun to read and that you now have a little better understanding and appreciation of this beautiful queen of a gemstone!
I’ll be back in a couple of weeks with something completely different, so until then, have a wonderful time wherever you are!
How can June nearly be over?! It was still snow outside like literally two months ago! We sort of skipped spring here in Sweden and went straight to scorching summer temperatures which was quite a chock for this gal here who isn’t built for such warm weather.
Anyway. June. A month which not only has one but TWO birthstones: moonstone and pearl, and today it will all be about the forever timeless pearl.
Freshwater pearl jewellery set in 14k gold fill.
“Pearls are always appropriate” – Jackie Kennedy
Pearls are with no doubt the most timeless, classic and sophisticated gem out there. It is regarded as one of the true precious gemstones together with diamonds, rubies, sapphires and emeralds and might even be the best-loved gem of all time.
Top: simple baroque freshwater pearl pendant paired with a luxurious 14k gold fill chain with elongated links. Bottom: handknotted freshwater and baroque pearl necklace using white silk thread and finished with a modern and minimal sterling silver toggle clasp.
Pearls – the beautiful result of a defence mechanism
First things first, what is a pearl?
A pearl is in fact an organic gem that forms inside of a living saltwater or freshwater mollusk.
Pearls are made up of concentric layers of calcium carbonate, CaCO3, either aragonite or a mixture of aragonite and calcite. The layers are held together by an organic horn-like compound called conchiolin. The combination of the two (calcium carbonate + conchiolin) is called nachre – the stuff that makes up the beautifully iridescent mother-of-pearl.
Left: the calcium carbonate mineral aragonite, here in crystal form. Top right: natural pearls in cross section clearly showing their concentric rings all the way through to the center of the pearl. Bottom right: the beautiful iridescence of nachre – Mother of Pearl.
The formation of a pearl begins with an irritant inside of the mollusk. The irritant could be organic, a parasite or a tiny speck of sand that found its way inside.
As soon as an irritant settle on the soft tissue it gets enveloped by a pearl sac – a layer of mantle tissue cells which make up the protective membrane on the inside of the mollusk shells. The pearl sac acts as a defence mechanism which seals the irritant off from doing any harm and then nachre is secreted, layer by layer, slowly building up a pearl. Typically, the build-up of a naturally forming pearl takes a couple of years.
Pearl sacs that eventually will become full grown pearls.
Perfect shining little spheres of delight
Due to the unique conditions under which natural pearls form they come in a dazzling array of sizes, colours and shapes. Perfectly round ones are actually very rare.
Below I’ve listed some of the most basic shapes:
Round
Semi-round
Button
Drop
Pear
Oval
Baroque
Circled
Perfectly round pearls are the rarest and most valuable shape. Semi-rounds are often used in necklaces or in pieces where the shape of the pearl can be disguised to look lite it’s a perfectly round pearl. Button pearls are like a slightly flattened round pearl. Drop and pear-shaped pearls are sometimes referred to as teardrop pearls. Baroque pearls are often highly irregular with unique and interesting shapes. Circled pearls are characterized by concentric ridges, or rings, around the body of the pearl.
The many shapes of pearls. Bottom right from the left: circled, baroque, button, drop and round.
Natural vs. cultured pearls
Natural pearls are nearly 100% calcium carbonate and conchiolin (nachre) grown in concentric layers by mollusks in the wild with no human involvement. Natural pearls are actually incredibly rare, and in the past many hundreds of pearl oysters or mussels had to be gathered and opened, and thus killed, to find even one wild pearl. Their scarcity was the reason for their then extraordinarily high prices.
Today natural pearling is confined mostly to seas off Bahrain and Australia, and to spare any mollusks not carrying pearls all mollusks goes through an X-ray examination in order to reveal any hidden pearls within.
Left: antique natural pearl and 19ct gold necklace. Right: antique natural pearl necklace with diamond clasp.
Cultured pearls are formed in pearl farms, using human intervention as well as natural processes.
In the pearl farms, a tiny piece of mantle tissue from a donor mollusk is implanted into the recipient mollusk to kickstart the pearl-forming process. To get perfectly round pearls, they often use spherical beads of mother-of-pearl as the nucleus. The use of an implant like this enables cultured pearls to be harvested much faster, just after six months.
Top: pearl farming in Fiji. Bottom: pearl extraction process.
Cultured pearls can be distinguished from natural pearls by X-ray examination since their interior gives them away.
Since cultured pearls are often ‘preformed’ they tend to follow the shape of the implant. When a cultured pearl with a bead nucleus is X-rayed, it reveals a different structure to that of a natural pearl. A beaded cultured pearl shows a solid centre with no concentric growth rings, whereas a natural pearl shows concentric growth rings all throughout. Their interior is of course also visible if you cut the pearl in half.
Top: illustration of the difference in interior between a cultured and natural pearl. Bottom left: cultured pearl cut in half clearly lacking concentric rings. Bottom right: natural pearls in cross section with obvious concentric rings all the way to the center.
Pearls, pearls, pearls!
The vast majority of pearls sold today are cultured in pearl farms and comprises mainly of four types: akoya, South Sea, Tahitian and freshwater.
Akoya
Pinctada fucata (akoya pearl oyster)
Introduced to the market in 1916 as the first ever spherical cultured pearl
Bead and non-bead cultured
Environment: pristine saltwater far from cities
Location: Japan and China, larger sized pearls (≥ 8.5 mm) are generally from Japan
Colours: white or cream, some with hints of pink or green
Size: generally between 3-7mm but can occasionally reach 9-10mm
Top: a classic white pearl necklace made with akoya pearls. Bottom left: akoya pearl in her akoya oyster shell. Bottom right: the subtle overtones of the akoya pearls: silver, rose and cream.
South Sea
Pinctada maxima (silver- or gold-lipped pearl oyster)
Culturing began: 1950s
Bead and non-bead cultured
Environment: saltwater
Location: between the northern coast of Australia to the southern coast of Southeast Asia passing the Phillipines as well as Myanmar
Colours: silver, white and golden
Size: generally between 8-16mm but can very occasionally reach over 20mm
Left: golden South Sea pearls on top of the golden-lipped oyster shell. Right: the golden colour scheme of the South Sea pearl.
Tahitian pearls
Pinctada margaritifera (black-lipped pearl oyster)
Colours: eggplant purple, peacock green, metallic grey and greyish blue
Size: generally between 7-12mm but can very occasionally reach over 16mm
Top left: baroque Tahitian pearls. Top right: beautiful Tahitian drop pearl pendants made by Malin Ivarsson. Bottom right: the many overtones of Tahitian pearls. Bottom left: a Tahitian pearl in the shell of a black-lipped oyster.
Freshwater pearls
Hyriopsis cumingii or hybrid
Appeared on the market in 1971
Bead and non-bead cultured
Environment: freshwater, usually cultured in lakes and ponds
Location: China, Japan and Tennessee, U.S.A.
Occur in a wide range of sizes, shapes and colours
Top and bottom left: the many shapes and colours of freshwater pearls. Bottom right: each freshwater pearl oyster can grow several pearls at once, resulting in a high production and thus cheaper prize.
How to care for your pearls
Pearls are, due to their soft calcium carbonate mineralogy, unfortunately easily scratched. Therefore they need to be handled extra carefully, both when wearing and when storing them, in order to maintain their beauty.
A first rule of thumb when dressing is: pearls should be the last thing you put on and the first thing you take off. This rule can and should be applied to all kinds of gemstone jewellery to maintain their beauty.
Below is a few pointers to keep in mind for keeping your pearls looking shiny and new to last a lifetime.
Cleaning
For routine care, after each wearing, wipe your pearls with a very soft and clean cloth to remove any residues from the skin.
For occasional, thorough cleaning, use warm and soapy water . If the pearls are strung, be sure the silk is completely dry before wearing.
Storing
Store pearls separately from gems and metal jewellery, which may scratch their surface. Instead, store them wrapped in a piece of silk or satin.
Never store pearls in a plastic bag. Plastic can emit a chemical that will damage their surface. The same is true of cotton wool.
Never store pearls in a well-sealed box for a long time. Like your skin, pearls need a little moisture so they will not dry out.
Wearing
Pearls can be damaged by many chemicals and all acids. The list includes hair spray, perfume, cosmetics and even sweat. Always apply perfume, hair products and perfume before putting on your pearl jewellery. And remember, this can be applied to all gemstone jewellery.
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There, this post turned out quite long and I don’t blame you if you just skimmed it. But if you read the whole thing, THANK YOU!
The blog post about June’s second birthstone, the moonstone, need to unfortunately be postponed. I’m busy busy preparing for a rock and jewellery show that’s taking place in a month’s time, I hope you don’t mind. To see some behind the scenes on me hustling away you are more than welcome to stalk me on instagram 🙂
It’s just a couple of days left of May which means I’m all caught up with my birthstone blog posts (phew)! May has been an amazing month weather wise here in Sweden, we’ve had sun and summer warmth for nearly 4 weeks, more or less the whole month! Let’s just hope it continues to be this good throughout the actual summer months *fingers crossed*
Anyway, back to what I was talking about, the May birthstone!
May birthstone jewellery handmade with beautiful translucent green emeralds and paired with 14k gold fill or sterling silver. Made by me.
A Brief History Lesson
Emeralds have been known for more than 4000 years and were first discovered in Egypt where they were admired by none other than Queen Cleopatra herself. Apart from being beautiful, emeralds were highly valued because they were believed to increase intelligence, protect marriages, ease childbirth and thought to enable its possessor the power of predicting future events. Now wouldn’t that be neat!
Left: ancient Egyptian gold and emerald necklace from ca. 204 – 30 BCE. Right: ancient Roman gold and emerald necklace.
At the present, emeralds are still highly valued, but nowadays it all has to do with their aesthetic. The country that produces not only the best ones but also the most ones is Colombia. Colombia is by far the leading producer of gem quality emeralds and accounts for about 70-90% of the world production, depending on the year, source and grade of the emeralds mined.
A beautiful and unique variety of the emerald, the “trapiche” emerald, is found here. These are distinguished by a six-pointed radial pattern of ray-like spokes of dark impurities.
Left: polished slice of a trapiche emerald. Right: trapiche emerald cut en cabochon and made into a stunning and unique ring by Jamie Joseph, available at New Twist.
Colombian emeralds are highly popular due to their purity. Their purity is thought to be due to their host rock, the rock in which they grew, which is of sedimentary origin. All other emeralds are found within igneous rocks such as pegmatites (read more about pegmatites here). So far the Colombian emeralds are actually the only ones found within sedimentary rocks.
Fun fact: the Colombian emeralds were in fact formed during the formation of the Andes that stretches along the whole of the west coast of South America.
The Evergreen Emerald
Emeralds are part of the beryl family together with aquamarine, morganite and heliodor amongst others. You can read more about the beryl family and its gemstone members in my previous blog post about aquamarines here.
Emeralds get their beautiful green colour from trace amounts of chromium and sometimes vanadium in its crystal lattice. Emeralds have a hardness of about 7.5 – 8 on Mohs hardness scale. For comparison quartz has a hardness of 7 and rubies and sapphires have a hardness of 9. As with all other beryl members, emeralds have a hexagonal crystal structure.
Emerald crystals showing their characteristic green colour and the distinctive hexagonal shape found within the whole beryl group.
Treatment
Unlike most of the other members of the beryl group though, emeralds are usually highly included and can have tiny fractures within which sometimes might reach the surface of the stone. This means their resistance to breakage is generally poor. This also means that most emeralds are treated to improve their stability.
Left: tiny inclusions within an emerald. Right: an A quality emerald on top versus an AAA quality emerald below, note the difference in the amount and appearance of inclusions.
The common treatment is with oils with a similar refractive index as emeralds to ensure the treatment won’t change its lustre or colour. For the oil to be absorbed more effectively, it’s applied within a vacuum chamber under mild heat in order to open up the pores in the stone and allow the oil to properly fill in the fractures.
This kind of treatment is very common nowadays, but sellers of emerald gemstones still need to inform potential buyers if a treatment has been done since any kind of treatment lowers its value.
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Well this post turned out to be short but sweet and I hope you enjoyed it – thank you for reading, you’re a gem!
Finally! I’ve had so much going on in my life the past two months (moving, preparing for a presentation, started working again) that I have not had the time to finish and publish the April birthstone blog post. But better late than never they say so here you go!
And now this one is gonna be a goodie, I love the science behind diamonds – science that is super unique, cool and that still has scientists wondering! But I had to cut back on the info that I had originally written because I tend to be an over achiever and not know when to stop, don’t worry though, you’ll still get plenty much of fun and interesting facts about this famous gemstone!
Diamond jewellery made with raw silvery grey 2-3mm Diamonds and 14k gold fill. Delicate birthstone jewellery for everyday wear. Handmade by me.
But first I need to be honest with you. I’ve never been that interested in diamonds, diamond jewellery that is. Particularly diamond jewellery with diamonds that fulfil all of the four C’s perfectly. But give me a diamond with a “flaw”, a rough surface, with some interesting inclusions or a more unique cut and shape, and I’ll be completely captivated and drooling over the floor!
Now, let’s start with some back story of the diamond gemstone.
The History of Diamonds
Diamonds have likely been known for as long as 6000 years and are thought to have been first discovered in India. There diamonds were found in alluvial deposits* along rivers. In the early days the diamonds were used as religious icons as well as in engraving tools due to their great hardness.
Ancient diamond jewellery. Left: Roman diamond ring from the 3rd-4th Century AD. Right: Indian diamond pendant necklace (www.pinsdaddy.com).
The popularity of the diamond started to rise significantly from the middle of the 19th century when diamonds where found in South Africa. Due to increased supply, improved cutting and polishing techniques, growth in the world economy, and innovative and successful advertising campaigns it quickly became the most valued and popular gemstone.
“Diamonds are a girl’s best friend.”
“Diamonds are forever.”
Today diamonds are mainly used for two things: personal adornment and industrial use.
*Alluvial deposits are vast deposits consisting of eroded material that’s been transported by gravity and water and accumulated in the base of a mountain.
Diamond Science
A diamond is a crystallised form of carbon (C) within the cubic crystal system. It’s the hardest natural material known to man, mostly due to the strong covalent bonding between the atoms in its diamond cubic crystal structure. This type of crystal structure is made up of a repeating pattern of 8 carbon atoms that the diamond adopts as it crystallises. This pattern is really hard to explain so I will not even try to go there and just leave you with this illustration of it below instead.
If grown unhibited their crystal structure enables them to grow into perfectly shaped crystals. The most common pure shapes are: cubes, octahedrals and dodecahedrons.
Three common diamond crystal shapes found: a cube (bottom left), an octahedron (upper right) and a dodecahedron (bottom right).
What I find really awesome though is that diamond as well as graphite are both solely made up of carbon, but diamond came to be the hardest material known to man while graphite is the softest, hence its use in pencils. This big difference in hardness has all to do with in which conditions (pressure and temperature) they were individually formed, which in turn decide their crystal structure and thus their hardness.
Fun fact: at the Surface of the Earth, graphite is actually the stable form whereas a diamond is actually metastable. This means that a diamond with time could convert to graphite. But don’t worry, this conversion would probably take billions of years which means your precious diamond jewellery is safe. Unless you have eternal life. And if you do, I want to know your secret!
Fun fact II: if a diamond gets engulfed by a fire it will literally burn up and only leave a pile of ash in its place.
Diamond Sources
Diamonds are extremely rare, with concentrations of at most parts per billion in their kimberlite host rock. Before the 20th century most diamonds were found in alluvial deposits where they are found in much greater quantity. Loose diamonds are also found along existing and ancient shorelines, where they tend to accumulate because of their size and density.
Left: a diamond in its host rock, a kimberlite. Right: a diamond in a piece of sedimentary alluvial deposit.
Where and How Diamonds Form
Most diamonds come from the Earth’s mantle, where they form deep below the surface of the Earth (about 150 – 250 km) under immense pressures and temperatures. Diamond formation is favoured by a thick lithosphere (crust + the uppermost rigid layer of the mantle) which can be found in continental areas with old (2.5 billion years old or more) stabilised crust. Such geological features are called cratons and can be found within all of Earth’s continents.
Left: the layers of the Earth. Diamonds form within the lithosphere which is the topmost two layers. Right: Cross section of the lithosphere over a craton, showing its thickness and where the diamond formation zone is.
However, there are other sources. Some blocks of the crust, or terranes, have been buried so deep as the crust thickened that they experienced ultra-high-pressure metamorphism. These terranes have evenly distributed microdiamonds that show no sign of transport by magma.
Also, when meteorites strike the ground, the shock wave can produce high enough temperatures and pressures for microdiamonds and nanodiamonds to form. These types of diamonds can be used as an indicator of ancient impact craters.
Both these last two sources produce diamonds that are way too small to be used in the jewellery industry.
Surface Distribution
Diamonds are far from evenly distributed over the Earth. Though they are almost always found in kimberlites on the oldest part of cratons which makes them easier to find. Kimberlite is a type of volcanic rock that forms at even greater depths than diamonds. As the kimberlitic magma ascends during an eruption, any diamonds within its path gets caught.
World map showing the location of all kimberlites currently found.
The science behind kimberlite formation and how it ascends to the surface during an eruption is still not clear. But what scientists do know is that the whole eruption process has to be fast enough in order for diamonds to still be diamonds when they arrive at the surface of the Earth. If the eruption were to be too slow, the diamonds would have time to convert into graphite before arriving to the surface.
The Four C’s
As you may know, a diamond is graded based on the four C’s: carat, cut, colour and clarity. This method got developed in the 20th century by expert gemmologists and is based on the characteristics most important to a diamonds value.
Carat – a diamond’s weight, 1 ct = 200 mg
Cut – the quality of the cut is graded according to proportions, symmetry and polish
Colour – how close to white or colourless a diamond is; for coloured diamonds, how intense the hue is
Clarity – how free a diamond is from inclusions
Apart from the four C’s, diamonds are also cut into different shapes which all reflects the light differently, giving each shape their own unique appearance and characteristics.
Diamond shapes.
Fun fact: a large (≥100 carats or 20 g) and flawless diamond is known as a paragon and such a diamond is considered to be a perfect diamond.
Fancy Colour Diamonds
Fancy colour diamonds are a collective name given to diamonds that display a colour. The rarest and most valuable colours are saturated pinks, blues and greens. In all cases, even very slight colour differences can have a big impact on value. Other colours that falls into the ‘Fancy Colour Diamond’ category is yellow, brown, red and blue. Red and blue diamonds are extremely rare whereas brown diamonds are the most common and yellow diamonds are the second most common.
Fancy coloured Diamonds in a variety of cuts and shapes (www.kimberfire.com).
Salt and Pepper
As I’ve already mentioned, a diamond that fulfil the four C’s doesn’t interest me that much. They are still beautiful but for me they lack that something extra: personality. I remember when I first started seeing included diamond jewellery on Instagram (where I hang out way too much these days) and I was amazed by their uniqueness, natural beauty and character. This particular diamond, named ‘Salt and Pepper’ diamond, first appeared on the market about 10 years ago and has been inching its way up in popularity ever since.
Dreamy Salt and Pepper Double Diamond Ring and Diamond Leaf Earrings by Katie Carder.
‘Salt and Pepper’ diamonds are characterized by white (salt) and black (pepper) inclusions scattered within and tend to be more silvery grey in colour rather than colourless. This type of diamond is often accompanied with a simpler type of cut such as a rose cut (my personal favourite cut btw).
Amazing rose cut diamonds in various shapes sold by Caleb B. Quashen.
A ‘Salt and Pepper’ diamond is not only beautiful, unusual or unique, it also shows you how beautiful flaws really can be and how they only add to their appearance.
So take it from these diamonds, flaws are BEAUTIFUL, they are a part of who you are, so let them be seen and be YOU!
Beautiful Salt and Pepper Diamond Rings by Meri from Gardens of the Sun.
Now, I’d love to hear what your favourite diamond looks like. Is it colourless or coloured, clear or included, raw or faceted? Please do leave a comment below and let me know!
Mother’s Day is just around the corner here in Sweden so I thought it would be fun to give you guys a few ideas for some amazingly thoughtful jewellery gifts your Mother is sure to love and cherish for a long time. And what Mama doesn’t deserve to be spoiled!?
Ever since I became a Mom almost 1,5 years ago now I love wearing jewellery that reminds me of my precious and wild little boy who has stolen my heart. So my two first gift ideas comes from what I feel when wearing them: happiness and an immense love.
Gift idea number 1: an Everlasting Birthstone Necklace
Birthstones have been around for centuries and are still going strong. I love the fact that each month got its own particular gemstone, some of them even got two. And to wear a birthstone represented by someone I love makes me feel close to them.
I made my first birthstone necklace roughly four years ago and then made it with gemstones representing me and my husband’s birthstones as well as for the months for when we met, got engaged and got married. Since then I’ve refined my design and now offer single birthstone necklaces in my shop. However, if anyone would like to have a necklace with multiple birthstones, I would be happy to help!
This necklace is completely new in my shop! The one pictured is the prototype, which I made during a silversmithing class I took during the spring of this year and of course I had to stamp the initial of my son’s name on it. This necklace is currently my favourite and I wear it nearly daily as it goes with everything. I just love the minimalistic design of it and to have my son close.
It’s completely handmade from a rectangular piece of sterling silver sheet. I saw out a roundish shape by hand and file and sand the edge smooth. Then a hole is drilled on top and the initial of your choice is stamped in the center. When that’s done it goes into the tumbler for a final polish before assembling it to a necklace ready to be loved and cherished by the wearer.
Since it’s handmade each pendant will vary slightly in shape and size making each pendant unique.
My third and last gift idea for this Mother’s Day is related to a good cause close to my heart. I love getting gifts that in some way matters. Either for me or for whom I bought it. It might be that the gifter put some real thought behind the gift, that the money spent on the gift goes to support a small or local business or that it goes to support a charity of some sort.
Gift idea number 3: the Ovarian Cancer Awareness Pendant
This pendant was made after the request from a lovely friend of mine who has fought against ovarian cancer for a couple of years now while also raising her young son on her own. She wanted a simple design that could be worn every day and that had a teal coloured gemstone, to represent the colour dedicated to this type of cancer. She chose to go with the turquoise gemstone and luckily I had a bunch of fine silver charms that looked just like the cancer ribbon symbol and the pendant was born.
This pendant is sold as a means to support not only my friend’s fight against ovarian cancer but to support all women in Sweden who are currently fighting. When you buy this necklace, all of the proceeds will go towards this cause.
It’s time to dig deep into the science of the gemstone aquamarine and its mineral family today. This post will definitely be more science-y than my last post about birthstones which was about the amethyst, which can be considered a fairly “simple” gemstone.
I’m so excited to teach you all about this pastel blue dream of a gemstone and its mineral family so let’s just dive right on in shall we!
The aqua stone
The name aquamarine came to surface in the early 18th century and is derived from the latin aqua marina which literally means ‘seawater’ and is of course a reference to its sea-blue colour. The gem has been a popular talisman to wear by seafarers for centuries since it was said to protect them during their travels by sea, as well as from drowning and seasickness. I might test this theory for my next time on the sea since I get seasick very easily..
Delicate, minimal and everyday jewellery featuring aquamarines. Made by yours truly.
The beryl family
The gemstone aquamarine is one of 8 varieties within the popular beryl family, all of which are characterized by their specific colour, and I’m sure you have heard about most of them. Beryl is a mineral which is most commonly found in granitic* pegmatites** where it has been found in epic sizes several meters tall!
Left: giant beryl crystals found in 1928 at the Bumpus Quarry, Albany. Right: beryl crystal in quartz.
* The word ‘granitic’ is referred to its mineral composition, which in this case is composed of quartz, feldspar and mica, minerals that you would find in a common granite.
** Pegmatites are rock formations that form in the later stages of a granitic magma chamber’s crystallisation. Pegmatites are characterized by their larger crystal sizes which can be 2.5cm to several meters in size. The bigger crystal sizes within these rock formations is due to a very slow cooling process, which allows the crystals to grow BIG.
Top left: granite. Top right: pegmatite. Notice the hammer in the lower left corner for scale. Lower left: where pegmatites form relative to the granitic magma it originated from. Lower right: pegmatite intrusion covering a massive cliff face.
Beryl is a beryllium aluminium cyclosilicate mineral with the chemical formula Be3Al2(SiO3)6. To explain, cyclosilicate or ring silicate refer to the arrangement of the Si (silica) and O (oxygen) atoms within the crystal structure. When it comes to the beryl, these atoms are arranged in such a way that it gives the beryl crystal its characteristic hexagonal shape.
Left: the atomic arrangement in a cyclosilicate mineral. Blue spheres are oxygen (O) and red spheres are silica (Si). Right: the hexagonal shape of the beryl, aquamarine variety.
Beryl varieties
Pure beryl is colourless, but it is frequently tinted by impurities; possible colours are blue, green, yellow, pink and red. All of these colours represent one or two specific beryl varieties.
Blue – aquamarine and maxixe
Green – emerald
Yellow – golden beryl and heliodor
Pink – morganite
Red – red beryl or bixbite
White / colourless – goshenite
Aquamarine
Aquamarine is the blue or cyan variety of beryl and can be found at most localities which yield ordinary beryl. The deep blue version of aquamarine is called maxixe which is most commonly found in Madagascar. The pale blue colour of aquamarine is attributed to Fe2+ ions, whereas the deep blue colour of maxixe comes from when both Fe2+ and Fe3+ is present.
Advanced: The difference between the two Fe-ions is their oxidation state, which describes the degree of oxidation (loss of electrons) of an atom in a chemical compound. If an ion looses an electron to another element in the compound it gets a higher positive charge, if it gains an electron it gets a lower positive charge. Conceptually, the oxidation state is the hypothetical charge that an atom would have if all bonds to atoms of different elements were 100% ionic.
The largest gemstone quality aquamarine ever mined was found in Minas Gerais, Brazil, in 1910. It weighed over 110 kg and its dimensions were 48.5 cm long and 42 cm in diameter.
Aquamarine specimens. Left and right ones are from my own private collection.
Emerald
Emerald is, as most of you already know, the green variety of beryl. But spoilers, emerald is the birthstone of May which means it will have its very own blog post.
Golden beryl and heliodor
Golden beryl can vary in colour from pale yellow to a brilliant gold, with the colour being attributed to Fe3+ ions. The term “golden beryl” is sometimes synonymous with heliodor, but golden beryl refers to pure yellow or golden yellow shades, while heliodor refers to more greenish-yellow shades.
Left: heliodor and golden beryl beads in my own inventory. Note the slight difference in shade. Top right: heliodor. Lower right: golden beryl.
Morganite
Morganite is a rather rare gem. It is the pink variety of beryl and is also known as “pink beryl”, “rose beryl”, “pink emerald” and “cesian beryl”. It can vary in shades from light pink to rose. Orange/yellow varieties of morganite can also be found and colour banding is quite common. The pink colour is attributed to Mn2+ ions.
Pink beryl of fine colour and good sizes was first discovered on an island on the coast of Madagascar in 1910. In 1989, one of the largest gem morganite specimens ever uncovered was found in Maine, US. The crystal was 23 cm (9 in) long and about 30 cm (12 in) across, and weighed just over 23 kg (50 pounds).
Left: morganite with intergrown tourmaline. Right: morganite beads from my own inventory.
Red beryl
Red beryl, or bixbite, is the very rare red variety of beryl. As with morganite, red beryl gets its colouration from Mn, but from Mn3+ ions and not Mn2+ ions as in the case of morganite. As of to date, red beryl has only been found within the United States. The greatest concentration of gem-grade red beryl comes from the Ruby-Violet Claim in the Wah Wah Mountains in mid-western Utah. Unlike most other beryl varities, red beryl is usually highly included.
While gem beryls are ordinarily found in pegmatites, red beryl occurs in topaz-bearing rhyolites. Rhyolite is a volcanic rock and can be considered as the extrusive equivalent to the plutonic granite rock. Red beryl is formed by crystallising under low pressure and high temperature along fractures or within near-surface cavities of the rhyolite.
Red beryl. Note the high amount of inclusions. Perfectly imperfect in my opinion!
Goshenite
Goshenite is the colourless beryl variety and its name originates from Goshen, Massachusetts, where it was first discovered. The gem value of goshenite is relatively low and it can be found to some extent in almost all beryl localities.
Since pure beryl is colourless, one would assume that goshenite is the purest of them all. However, this assumption may not always be true as there are several elements that can act as colour inhibitors in beryl.
Goshenite specimens. The one on the right features an intergrown tourmaline crystal and colour impurities.
That’s a wrap
I hope you found this post interesting, I at least had a lot of fun writing it and doing some research on this interesting and beautiful mineral family.
So, if you ever want to find your own aquamarines or any of the other beryl varieties, the first step is to find yourself some pegmatite outcrops.
Welcome to blog post number two about birthstones (again, published in the last second). As you know I like to get science-y with these posts and probably use terms and jargons that you’ve never heard of. But I will try and explain everything as simple as possible for you. After all, I want you to understand what I’m talking about, so you can see why gemstones are so much more than just pretty minerals adorning the jewellery we wear.
How to not get drunk
February means it is all about the amethyst! Amethyst is, as many of you may know, the purple variety within the large quartz family with a simple chemical composition, namely SiO2. Since it’s a quartz variety, it has a hardness of 7 which means it’s very suitable for jewellery since it doesn’t scratch easily from everyday wear.
Amethyst got its name from the ancient Greeks who thought amethyst would keep them from getting drunk. The word amethystos literally means “not intoxicate”. They would wear or drink out of amethyst vessels in the belief that it would prevent intoxication.
Left: carved amethyst wine goblet. Right: my amethyst earrings in sterling silver.
Ultra Violet
If you didn’t know, the Pantone colour of the year for 2018 is Ultra Violet, which suits the deep purple colour of the amethyst pretty well if I do say so myself. Amethysts come however in many different purple hues, from a light pinkish violet all the way to that royal deep purple. The most valued colour of amethyst is the deep purple one and a deep purple that has a red tinge to it.
So how does amethyst get its purple colour? Simply put it all has to do with the presence of iron in its structure. Iron atoms may replace silicon atoms during the crystal’s formation. And we are talking trace amounts here, the amethyst wouldn’t be an amethyst anymore if a major part of the silicon atoms were to be replaced.
One thing that you should be aware of when it comes to the colour of the amethyst is that if it gets overexposed to sunlight, it can fade in colour. So, if you want to keep that deep purple colour of your amethyst jewellery or mineral specimen pristine, display or store it in a place with little to no sunlight.
The ametrine
A rough ametrine specimen with a clearly visible border between the amethyst and the citrine halfs.
Have you ever heard of the gemstone ametrine? The ametrine is a gemstone that is half amethyst and half citrine, which means it displays both purple and yellowish hues. This dual colouring is due to differing oxidation states of the iron within the crystal. And the differing oxidation states occur during the crystal’s formation (its crystallisation phase), as the temperature gradient across the crystal cools over time.
The formation of an amethyst
Amethyst crystals are always grown onto a base within a cavity of a host rock. This sort of rock with a sparkling surprise inside is called a geode.
Amethyst geode from Brazil. The crystals are grown onto a base consisting of agate.
Geodes are round to elongated rock structures which are hollow inside with minerals lining the walls. The base of the mineral lining is usually thin bands of translucent grey and white agate which the crystals then grow on top on. Geodes range in size from under one centimetre to several meters in length. From the outside most geodes look like common rocks, but when they are opened the sight can be breath taking. The outer wall of a geode is more resistant to weathering than the surrounding bedrock which allows it to survive intact when the surrounding bedrock weathers away.
Apart from amethyst crystals, other common geode minerals include quartz, agate and calcite. Some rare geodes can be filled with beautiful blue gem silica, pink rhodocrosite, spectacular opal or other rare materials.
Two beautiful geodes with spectacular mineral landscapes within. To the left: a basalt geode with mesolite and chalcedony. To the right: a basalt geode with blue chalcedony, calcite and mordenite bobbles. Both from India.
The formation of a geode
I bet you wonder how on Earth there can exist hollow cavities within solid bedrock, so I will tell you. Most geodes are found in volcanic rock deposits such as basalts. These are rocks that normally contain a lot of gases and it’s the gases that creates these cavities. When the lava cools and solidifies, any gases that hasn’t been able to escape gets trapped and thus create cavities within. Another way a cavity can form in volcanic rocks is by liquid lava flowing out of a partially solidified lava flow. These ‘lava tube’ cavities produce some of the largest and longest geodes.
Several amethyst geodes within an ancient basaltic lava flow.
Geodes can also be found in sedimentary rocks such as limestones, dolomites and calcareous shale. Within these rocks, shells, tree branches, roots and other organic materials often decay away to leave a void. These geodes are generally smaller than the geodes formed in volcanic rocks.
What all of these cavities has in common is that their mineral lining is due from mineral rich hydrothermal water or groundwater finding their way in and precipitating mineral material over a long period of time. And it’s the mineralogy of the surrounding rocks and the minerals within the water that decides which minerals will form within the geode.
So, if you want to find some amethyst crystals yourself, look for geodes within old basaltic lava flows!
. . . . .
So that’s that – I hope you enjoyed this blog post and that I managed to make you look at an amethyst in a completely new way!
So Valentine’s Day is just around the corner so I thought it would be fun to highlight three unique jewellery pieces in my shop that would make for an awesome gift for your Valentine, Galentine or yourself for that matter!
So let’s jump right in and start with number 1: the OOAK necklace
Who wouldn’t want something truly one of a kind?! The gemstones I used in these necklaces are just super freaking incredible! Both necklaces features included quartz gemstones, and by included I mean gemstones that have another visible mineral within. You can choose between either a tourmalinated quartz or a lepidocrocite included quartz (or as I like to call it, a confetti quartz).
The tourmalinated quartz features a number of thin black tourmaline needles clearly visible within the clear quartz, whereas the confetti quartz features a fun and unexpected burst of metallic red to orange lepidocrocite inclusions within the otherwise clear quartz. Both of these gemstones are completely unique and no gem drop will look like the other, which means that you and only you will own a necklace that looks like yours! A one of a kind gift to a one of a kind woman!
These earrings are popping with colour and their dainty size and minimalistic yet boholiscious design makes them perfect for everyday wear!
You have three different berries to choose from: lingonberries, blueberries and cloudberries. All of these berries can be found more or less growing all over Sweden, only the cloudberry is more sparse due to its more northern and wetter climate preferences. I chose the stones for this collection very carefully, I wanted the stones to mimic the real berries as true as possible, both in colour and appearance.
The lingonberries features bright red bamboo coral. This is a type of colourless coral that grows in the deep sea and is dyed red to mimic the highly endangered red precious coral. The blueberries features blue dumortierite beads with a marbled look and with a matte surface. Dumortierite is the mineral that is the cause for blue-coloured quartz. The cloudberries features tiny carnelian beads that I have meticulously wire wrapped into small orange spheres.
And gift idea numero 3: fine silver stacking rings
Can you ever have too many stacking rings, I think not! You have three designs to choose from: a simple smooth and round design, a hammered design and a wrap design.
These rings are made from scratch using a thin fine silver wire that I fuse together to a closed ring with a torch. Since fusing fine silver literally means you heat up the metal until it melts and starts to flow, each ring turns out unique with an organic looking form, this is particularly evident in the round and smooth ring deisgn. These rings are lightweight and hardly ever tarnish due to its high almost pure silver content. Effortlessly chic and uncomplicated jewellery!
That’s my simple little gift guide for you for this Valentine’s Day, and any other gifting holiday throughout the year really. I hope you enjoyed it, I sure did so watch out for more gift guides coming this year!
So, it’s been a few weeks since my last blog post. I wanted to publish this particular one a little earlier but life got in the way and I definitely under estimated how difficult it would be for me to try to explain all of these science terms in an easy and understandable way, haha! But hey, it’s still January so as I see it, I made it just in time!
Garnet and 14k gold fill jewellery from my birthstone collection.
Anyways, this is the first post of what will be a monthly series about birthstones. Each month I will write a post dedicated to its respective birthstone(s) and give you facts about its different properties (colour, shape, hardness), where it can be found and other interesting facts.
I’m going to let my inner geology nerd shine through in these posts which means they will be jam packed with science! But don’t worry I will try and make it fun, interesting and easy for you. My goal is to make you look at each gemstone in a completely new light.
The glorious garnet
January is of course dedicated to garnets, one of my favourite gemstones due to its beautiful colour diversity, well-developed crystal shapes and it’s geological importance (I’ll come back to that). And also, it’s my birthstone!
One of a kind grossular garnet earrings.
Garnets have been used as a gemstone since the Bronze Age due to its commonness, beauty and durability. The word garnet can be thought of as a combination of two old words: the 14th-century English word gernet, which means ‘dark red’, and the Latin word granatus, from granum (‘grain, seed’). The second one is possibly a reference to pomum granatum (pomegranate) whose fruits contain abundant and vivid red seed covers, similar in colour to red garnet crystals.
Garnets me and my husband collected from the gold mine where we first met. These were lying in the granites surrounding the gold ore.
Garnets are common and widespread minerals and can be found all over the world. They are particularly abundant in metamorphic rocks. Metamorphic rocks are rocks that have been altered by high pressure and temperature during for example a collision that forms mountains and turns granites into gneisses or limestones into marbles.
Although garnets form in all of the colours of the rainbow, garnets are often easy to recognize because they are generally found as well-developed crystals in a cubic crystal form, usually occurring as dodecahedrons, trapezohedrons or a combination of the two. I know, I know, you have no clue what those words mean, but the picture below might do the trick.
The many looks of garnets. Top row: dodecahedron (far left) and dodecahedron + trapezohedron combinations. Bottow row: trapezohedron (far right) and trapezohedron + dodecahedron combinations.
The geological importance of garnets
Garnets are more than just beautiful, they play an important role for geologists trying to figure out the genesis of garnet-bearing rocks. Garnets work like record keepers, they store the conditions of which they were formed and altered in. This means that geologists can figure out the temperature and pressure and hence the depth of where a garnet-bearing rock originated. This particular science is called geothermobarometry and was one of my favourite subjects when studying geology! I felt like a detective, figuring out where a particular rock came from and what it had been through since its formation.
The many species of garnets
So, garnets come in a wide variety, can you guess how many garnet species there are? Fifteen! They all follow one general chemical formula: X3Y2Si3O12 , where X can be either calcium, ferrous iron, magnesium or manganese, and Y can be either aluminium, ferric iron, chromium, manganese, silicon, titanium, zirconium or vanadium.
The six largest and most common species are:
Almandine Fe3Al2Si3O12
Pyrope Mg3Al2Si3O12
Spessartine Mn3Al2Si3O12
Grossular Ca3Al2Si3O12
Andradite Ca3Fe2Si3O12
Uvavorite Ca3Cr2Si3O12
Now, this is where it gets complicated, so bear with me as I try to explain. These six garnets are known as end-members and can be divided into two groups. Each group consists of three garnets which simply put mixes with each other during crystallization in what is called solid solution series. This means that almandine (Fe) can mix with both pyrope (Mg) and spessartine (Mn) and grossular (Ca) can mix with both andradite (Fe) and uvavorite (Cr).
With mixing I mean that a garnet is never 100% purely an almandine (100% Fe) for example. There is always a little bit of pyrope (Mg) or spessartine (Mn) mixed in. The name an individual garnet specimen is given is based on the chemical composition and the element (Fe, Mg or Mn) that has the highest percentage.
So, for example, if a garnet is analysed having 80% Fe, 10% Mg and 10% Mn in its composition, that garnet would be classified as an almandine. If a garnet has 60% Mg, 30% Fe and 10% Mn in its composition, it would be classified as a pyrope. And so on. If you take a look at the triangle below though, you see that the mixing has its limits. The yellow area represents the area of all the observed compositions found in garnets. The limitations are due to elemental behaviour during crystallization. I will not go into this further because this is a whole other very complicated topic.
The pyralspite garnets solid solution series. Each point of the triangle is dedicated to one of the three end-members and the yellow area represents their mixing area.
How to distinguish between the 6 most common garnets species
Although you can’t be 100% sure of what type of garnet you are looking at without a chemical analysis done in a lab, there are some features you can use to at least narrow down your guesses. Its colour and where you found it can give you some clues. So if you have some garnets laying around at home that you’d like to try and classify, read on! Below follows some short descriptions for each (major) garnet species that might be able to help you out during your detective work.
My private collection of garnet crystals. From the left: hessonite, spessartine, spessartine, grossular, demantoid, chrome grossular and tsavorite.
Almandine is the most common garnet species and have that deep red colour which garnets most often are associated with. Almandine garnets can be found in granites as well as in metamorphic rocks like mica schists and gneisses.
Pyrope is a fun garnet species because this garnet is an indicator mineral for high-pressure rocks such as diamond-bearing kimberlites, which means that they are used in diamond prospecting! Pyrope normally varies in colour from deep red to black which can make it hard to distinguish from almandine. Rhodolite is a violet-red to pink hued variety of pyrope which chemically is a 2:1 mixture of pyrope and almandine. Colour change or blue garnet is another variety of pyrope which is a mix of pyrope and spessartine. This is the rarest type of garnet. Apart from being found in kimberlites it can also be found in volcanic rocks, which means rocks that have been ejected on to the surface during a volcanic eruption.
Spessartine is most commonly known for its beautiful orange-yellow colour which it gets from the manganese in its composition. Spessartines are mostly more or less orange but they can also be coloured red by substituting the manganese with iron. A vivid bright tangerine orange variety has the aptly name mandarin garnet. Gemstone quality spessartine is rare but is most often found in granite pegmatites.
Grossular garnet can be colourless all the way to black, but it got its name from the green variety which resembled the gooseberry (grossularia) in colour. Other grossular varieties like hessonite are cinnamon brown to orange-red in colour. Tsavorite is a variety which is vividly green in colour. Chrome grossular is a bright green variety, often mistaken for uvavorite. Grossular is commonly found in contact metamorphosed limestones.
Andradite may be red, yellow, brown, green or black. There are three recognized varieties of andradite garnets: topazolite, demantoid and melanite. Topazolite is golden-yellow to olive coloured. Demantoid is yellow-green to emerald-green and has been called the ‘emerald of the Urals’, it is one of the most prized garnet varieties. Melanite crystals are opaque and black. Andradite garnets are commonly found in contact-metamorphosed limestone and in mafic igneous rocks.
Uvavorite is a rather rare garnet species which is bright green in colour. Uvavorite crystals are brittle and almost always too small to be cut as gemstones. Some of the largest crystals come from Outokumpu, Finland. Uvavorite is found in chromium-bearing rocks such as serpentines.
That’s all folks
I hope you enjoyed my first more science-y blog post about garnets. I had a lot of fun writing it but I have to admit, it took me quite a while and I’m still not sure I managed to explain everything good enough. But I had a deadline to stick to and hopefully I will get better at explaining with each birthstone post I write!
If you liked this post or if you have any questions about anything, please leave a comment 🙂
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