Pearls – the Birthstone of June

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 Pearls June Birthstone Jewellery Set in 14k Gold Fill
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.

Simple baroque freshwater pearl pendant paired with a luxurious 14k gold fill chain with elongated links. Handknotted freshwater and baroque pearl necklace using white silk thread and finished with a modern and minimal sterling silver toggle clasp. By Linda Sääv Jewellery.
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.

Aragonite Crystal, Cross Section of a Natural Pearl and Mother of Pearl Shell
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 in Oysters
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 Various Shapes of Pearls
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.

Antique Natural Pearl Necklaces
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.

Pearl Farming and Harvesting
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.

Natural vs Cultured Pearls in Cross Sections
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.


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
Akoya Pearls
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
South Sea Pearls
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)

  • Culturing began: 1960s
  • Bead and non-bead cultured
  • Environment: tropical saltwater, preferably clean-water lagoons
  • Location: French Polynesia
  • Colours: eggplant purple, peacock green, metallic grey and greyish blue
  • Size: generally between 7-12mm but can very occasionally reach over 16mm
Tahitian Pearls Black Pearls
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
Freshwater Pearls
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.

Caring for your pearls by Linda Sääv Jewellery

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.


  • 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.


  • 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.


  • 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 🙂

Until next time, I wish you a wonderful summer!

♥ Linda