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A pearl for you

By Lauriane Lognay

Baroque-shaped blue Akoya pearls. Photos by Perla Inc.
Baroque-shaped blue Akoya pearls.
Photos by Perla Inc.

If diamonds are a girl’s best friend, pearls are truly a woman’s treasure. Indeed, classic style is back in a big way. For many, this means pearls are taking centre stage.

Of course, nothing’s sweeter than a new twist on an old favourite. Today’s shoppers love retro-style bands and antique-inspired jewellery pieces, but cutting-edge jewellers have the skill to add their own modern touch to the bespoke pieces they craft.

For designers, every custom-ordered piece of jewellery is made in our image. Pearls are the ideal tool for this level of customization: these incredible gems are available in hundreds of shapes, plenty of types, and a huge palette of colours to suit any client’s needs.

More and more retailers are coming out of their shell to push the fashion forward with pearly jewellery, marketed at men and women alike. To ride the wave of this growing trend, let’s dive into the lustrous world of pearls.

Your type is my type

Oyster Pteria Sterna (rainbow-lipped), a mollusk for black/Tahitian pearls.
Oyster Pteria Sterna (rainbow-lipped), a mollusk for black/Tahitian pearls.

When it comes to pearls, all shapes are beautiful, and all types have their place in the market. Since there are more than 20 varieties of these incredible stones, this article will explore pearls in broad terms, including details on where to find specific types.

Pearls are generally divided into two big families:

  • saltwater pearls (oysters found in oceans, seas, etc.); and
  • freshwater pearls (mussels found in smaller bodies of water, like lakes and ponds).

Stemming off from these two families, there are many different types, detailed below.

Akoya pearls

Nature: Cultured saltwater

Mollusk: Oyster Pinctada Fucata, Pinctada Martensii, and Pinctada Radiata

Origin: Japan, China, United States, Korea, Sri-Lanka, United Arab Emirates, Hong Kong, and other locales

Akoya pearls are typically round and white, but, in today’s market, they can be found with many different overtones of colour. They usually measure 1 to 10 mm in diameter.

Contamination in the oyster sometimes occurs, causing the pearl’s colour to turn blue. In these instances, they are sometimes marketed as ‘blue pearls’ instead of ‘Akoya.’

‘Mikimoto’ is a well-known brand name of Akoya pearls. It is worth mentioning because the brand’s founder, Kokichi Mikimoto, was among the inventors of cultured pearl farming more than 120 years ago. His techniques continue to be used to this day.

South Sea pearls

Nature: Cultured saltwater

Mollusk: Oyster Pinctada Maxima (silver- or golden-lipped)

Origin: Philippines, Indonesia, Australia, across the French Polynesia, and Myanmar

Generally, the label ‘South Sea’ extends to any saltwater cultured pearl from the South Seas. These are large pearls (9 to 20 mm in diameter) with tones ranging from yellow, black, grey, and white. Like Akoya pearls, contamination in the oyster sometimes occurs, causing the pearl’s colour to turn blue. In these instances, they are sometimes marketed as ‘blue pearls’ instead of ‘South Sea.’

Black/Tahitian pearls

Nature: Cultured saltwater

Mollusk: Oyster Pinctada Margaritifera (black-lipped), Pinctada Mazatlanica (La Paz), and Pteria Sterna (rainbow-lipped)

Origin: Central Pacific Ocean, Eastern Pacific (between Baja California/Peru), French Polynesia, and other locales

Black pearls are typically grey to black in tone with beautiful secondary colours (for this reason, these are sometimes marketed with names like ‘pistachio’ or ‘peacock’). Some gem professionals refer to any pearl with a dark body as a ‘black pearl’ (whether treated or not). Pearls in this category sourced from French Polynesia are also called ‘Tahitian.’

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Freshwater pearls

Nature: Cultured freshwater

Mollusk: Mussel Hyriopsis Cumingii, Hyriopsis schlegelii

Origin: China, Vietnam, and Japan

Round Akoya pearls.
Round Akoya pearls.

Freshwater pearls can be found in all pastel colours, including hues of white, purple, cream, and coral. Considered the most cultivated and well-known type of pearl in the world, freshwater pearls can be found in every shape possible (be it naturally occurring or with a shaped nucleus).

Biwa pearls

Nature: Cultured freshwater

Mollusk: Mussel Hyriopsis Schlegelii

Origin: Japan’s Lake Biwa (originally) and China

Biwa pearls get their name from their original source, Lake Biwa, the largest lake in Japan. Due to pollution, the farming and production of pearls in this locale has become difficult. While there is also specific shape of flat baroque pearl found in China called ‘Biwa,’ these are not generally considered to be true Biwa pearl.

Kasumi/Kasumiga pearls

Nature: Cultured freshwater

Mollusk: Mussel hybrid between Hyriopsis schlegelii and Hyriopsis Cumingii

Origin: Japan and China

First sourced from Lake Kasumigaura in Japan, Kasumiga pearls are among the most colourful on the market. Ranging in size from 11 to 16 mm, they have a strong iridescence and are typically baroque-shaped. This type can have multiple colours in one, sometimes ranging from green to golden to purple in the same pearl. They are now also available on the Chinese market, where they tend to be called ‘Kasumi-type,’ ‘Kasumi-like,’ or ‘Ming’ pearls. Edison pearls are a type of Kasumiga and are considered by many to be the most beautiful variety.

Blisters

Nature: Natural or cultured in oyster or mussel shell

Mollusk: Any mussel or oyster

Origin: Any pearl-producing locale

Blister pearls are natural or cultured formations that grow on the surface of mussel or oyster shells. Unlike abalone and mabe pearls (detailed below), when blisters are cut, they are not assembled. Sometimes they are caused by an anomaly, like a small worm making its way into the shell and getting trapped by the nacre. They can also form as natural clusters of ‘pearls’ stuck to a shell.

Mabe pearls/Mabe blister pearls

Nature: Natural or cultured in oyster or mussel shell

Mollusk: Any mussel or oyster, but technically Pteria Penguin (mabe oysters)

Origin: Any locale with cultured pearls

Sometimes called ‘cultured pearl doublets,’ mabe pearls are assembled cultured blisters. Recognizable by a lip or rim around the protuberance (resembling an egg), they can be created by gluing a nucleus (plastic or nacre) or soapstone to the inside of a shell. When the shell finishes secreting nacre, the blister is cut out and the nucleus is removed. The hole is filled with paste, glue, or resin, and a doublet is made.

Rainbow pearls

Nature: Cultured saltwater

Mollusk: Oyster Pteria Sterna (rainbow-lipped)

Origin: Eastern Pacific coast between Baja California and Peru; also, Guaymas, Mexico (called ‘Cortez pearls’)

Measuring between 7 and 12 mm, rainbow pearls are known for their high lustre and iridescence compared to the other types of pearls on the market. They also enter in the category of black pearls—indeed, when considering rainbow, black, Tahitian, and Cortez pearls, it is easy to get a bit lost in the similarities! It is not unusual to see up to four colours in these types of pearls (hence the name). Once found naturally, production has since ended due to over exploitation and overfishing.

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Cortez pearls

Nature: Cultured saltwater

Mollusk: Oyster Pteria Sterna (rainbow-lipped)

Origin: Guaymas (Mexico)

South Sea pearls in natural colours.
South Sea pearls in natural colours.

The term ‘Cortez pearls’ is mostly used as a trade name for cultured saltwater pearls from Mexico’s Bacochibampo Bay in the Sea of Cortez. Scarce on the market and considered high quality, these pearls are often found in unique pieces of jewellery. While they resemble Tahitian and black pearl varieties, Cortez pearls can be distinguished using ultraviolet (UV) light reaction. They also tend to have a wider range of variety in their natural iridescent colours. This is the first cultured saltwater pearl farmed in America.

Seed pearls

Nature: Natural saltwater or freshwater

Mollusk: Any mussel or oyster

Origin: Any pearl-producing locale

The classification ‘seed pearl’ is typically used for natural pearls considered tiny enough for the name. They usually measure smaller than 2 mm.

Keshi pearls

Nature: Cultured saltwater and freshwater

Mollusk: Oyster and mollusk

Origin: Any pearl-producing locale

One of nature’s beautiful accidents, keshi pearls are spontaneously formed during a saltwater culture. They can be a black pearl, an Akoya, or even a South Sea. ‘Keshi’ is also a term used on the market for baroque-shaped pearls from freshwater cultures.

Mother of pearl

Nature: Natural or cultured

Mollusk: Any can be used

Origin: Any locale with mollusk

Mother of pearl is the interior of the shell of any mollusk. It is often used as beading, decoration, and incrustation. It is the lustrous nacreous part of the shell that is cut and carved.

Pipi pearls

Nature: Natural saltwater

Mollusk: Oyster Pinctada maculata

Origin: Cook Islands

The oysters used for this variety are among the smallest of the mollusk group capable of producing pearls. Pipi, in fact, is a Polynesian word, meaning ‘baby’ or ‘small.’ Measuring 2 to 8 mm in diameter, pipi pearls (also called ‘poe pipi’) are cream, peach, white, or golden in colour.

Oriental pearls

Nature: Natural saltwater

Mollusk: Oyster-wing shell

Origin: West Asia, Gulf of Mannar (west coast of Sri Lanka), and Persian Gulf

Considered one of the first types of natural pearls to be fished/found, Oriental pearls have been discovered for more than 2000 years. Quantities found, however, slowed significantly in the 1930s. Today, these nacreous pearls are considered more as collectables than gems used in jewellery.

Some argue true Oriental pearls only come from a type of oyster called the wing shell, while others believe specific classification is more dependent on where they are found. The subject stays divided.

Abalone pearls

Nature: Natural saltwater

Mollusk: Technically classified as a large snail named abalone (or Haliotis)

Origin: California coast, Oregon, Alaska, Mexico, Japan, Korea, New Zealand, South Africa, and Australia amongst other locales

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While the abalone shell is not, technically, an oyster or a mussel, abalone pearls are still considered part of the pearl family. They are sought-after by jewellers due to their unique baroque shapes. Abalone pearls can also be found as blisters.

Conch pearls

Nature: Natural saltwater

Mollusk: Found in a marine snail named Strombus gigas

Origin: Caribbean

Natural colours of freshwater pearls.
Natural colours of freshwater pearls.

With a porcelain-like appearance, non-nacreous conch pearls are desired largely because of their unusual flame pattern. These natural pearls are found in pink, creamy, orangey, and even chocolate colours.

Quahog pearls

Nature: Natural saltwater

Mollusk: Clam Venus mercenaria

Origin: United States’ North Atlantic coast

The non-nacreous Quahog pearl is most valuable when lavender or purple (conversely, the white variety is least rare/least expensive. It can also be found in cream, black, or brownish. Most Quahog pearls measure 7 mm or smaller, but varieties as large as 20 mm have also been found.

Scallop pearls

Nature: Natural saltwater

Mollusk: Scallop shell Nodipecten subnodosus (lion’s paw)

Origin: California coast and Canada

Ranging in colour from creamy white to orangey to purple, the non-nacreous scallop pearl naturally occurs in a scallop shell. What is interesting is its ‘discovery’ only occurred in the early 2000s! Scallop pearls are typically sought after by collectors and are not often used in jewellery.

Giant clam pearls

Nature: Natural saltwater

Mollusk: Clam varieties Tridacna gigas, Tridacna squamosal, and hippopus hippopus

Origin: Philippines, Indo-Pacific, and Red Sea locales

Non-nacreous giant clam pearls found are found mostly in white with occasional tones of colour. The largest of this variety was found in the Philippines and weighed 34 kg (75 lb.).

Nautilus pearls

Nature: Natural saltwater

Mollusk: Cephalopod Nautilus pompilius

Origin: Southeast Asia and Pacific Ocean

The Nautilus pearl is among the rarest varieties in existence. White in colour, these pearls are usually round or baroque shapes. Curiously, the inside of the Nautilus shell is nacreous, but the pearls found in them are not.

Faceted and carved pearls

While not necessarily new, per se, faceted pearls are not very well known. The act of faceting something original was often a curiosity for the lapidary artist, aimed at encouraging a jeweller to craft a unique piece.

Faceting pearls can sometimes make blemishes vanish on the surface and give some low-quality pearls renewed lustre on the market. Some jewellers even decide to put studs inside the pearls and decorate them with gemstones in some original concepts.

One for everyone

Pearls have carved a name for themselves in the jewellery market without the need for any commercial coup to up their popularity. Indeed, wearing pearls of all kinds has long been a custom in human history for men and women alike. These lustrous stones prove some traditions deserve their place in our modern jewellery world.

Lauriane Lognay is a fellow of the Gemmological Association of Great Britain (FGA), and has won several awards. She is a gemstone dealer working with jewellers to help them decide on the best stones for their designs. Lognay is the owner of Rippana Inc., a Montréal-based company working internationally in coloured gemstone, lapidary, and jewellery services. She can be reached via email at rippanainfo@gmail.com.

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2 comments on “A pearl for you”

  1. Good evening and thank you for the info and categorization.I believe I have a handful of conch pearls that are extremely old!some I think are different age and colors as well.they been certified by the g.i.a. and actually a small right up in the g and g publication. [Spring 2021 page 60 and 61 I believe.my next question is what to do with these?I’ve spoke with local geologists that have never of anything like this.many other fossils,shells,and teeth we’re discovered as well.all dating in between the plio,plesto,and, miocene.I would love to speak to you and appreciate any input!thanks in advance!!!

    1. Hi Aaron,
      First of all thank you so much for your comment! Always a pleasure to see people interested in what I write. As for the pearls that you have, you can always do amazing jewellery collections with them, or sell them to collectors and jewellers alike. My email is at the end of the article if you have anymore questions. Have a great day!
      Lauriane

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