Pearls have been valued and cherished for centuries by cultures around the world. Ancient Greeks believed pearls to be tears of joy, shed by the goddess of love, Aphrodite. Ancient Egyptians associated pearls with the goddess Isis. Arab legend declares that pearls are dewdrops filled with moonlight which fell into the ocean to be swallowed by oysters. Only the rulers of the Roman Empire were allowed to wear pearl jewellery in the first century B.C., as proclaimed by Julius Caesar. That tradition was also followed by royalty of the British Empire in their heyday. Even recently, pearls were worn almost exclusively by royalty and the wealthy upper class, as they were very expensive and no one else could afford them. Other references in great works of literature and art speaks to the importance and worth placed on pearls. According to the King James Bible, the very Gates of Heaven are made of pearls.
More readily available and affordable now than in the past, pearls still hold a special place in the hearts of many and their beauty is undeniable.
There are a few terms to be aware of when talking about pearls:
Freshwater and Saltwater Pearls
If a person is asked where pearls are produced, most people will think of the oyster. They’re not wrong, saltwater pearls do indeed grow in oysters. However there is a freshwater variety of pearl which are formed in several species of freshwater mussels. When buying pearls, you might see SWP, saltwater pearl or FWP, freshwater pearl. Saltwater pearls have been considered more valuable, as they were rounder and had a better lustre than freshwater pearls. Freshwater pearls tend to be more irregular in shape with a softer sheen. With recent improvements in pearl farming techniques however, FWP are now approaching the roundness and lustre so prized in the saltwater variety.
Natural and Cultured Pearls
Pearls form when an irritant finds its way into an oyster or mussel. That irritant is coated in a fluid in order to protect the soft tissue of the mollusc. In natural pearls, that irritant, which is usually a parasite and not a grain of sand (sorry to burst your bubble!) is an accident of nature, most often happening when the shell opens to allow the bivalve to feed. The formation of a cultured pearl is the same, the difference lies in the nature of the irritant and the method of introduction. A bead or a piece of shell is surgically implanted in the mollusc, and nature takes care of the rest.
Baroque Pearls
Baroque comes from the Portuguese barroco, meaning misshapen pearl. So a baroque pearl is simply a pearl that has no regular shape.
Nacre (NAY-ker)
I mentioned that the starting point for every pearl is an irritant that is coated in a fluid as a defence mechanism. That fluid is called nacre and is also known as mother-of-pearl. The inner lining of many mollusc species is made of nacre and of course, it is the main ingredient of pearls. Once the irritant is introduced, it is coated with layer upon layer of nacre. To give you an idea of the timeline, a mussel may take 3 years to mature to a point where it can be implanted with an irritant. Once in place, it can take another 3 years for the layers of nacre to reach the thickness required for a gem quality pearl.
Cyst Pearls and Blister Pearls
Where the pearl grows will have an important impact on its shape. A cyst pearl is grown entirely within the body of the mollusc and is a three dimensional form, the typical pearl familiar to us all. A blister pearl, or Mabe (MAH-bay) pearl grows against the shell and so is often quite flat.
Non Nacreous Pearls
This can be a little confusing. All pearls, nacreous and non-nacreous are made of the same thing; calcium carbonate. This calcium carbonate has two distinct crystal forms, calcite and aragonite. Aragonite has a more orderly crystal structure which allows the light to reflect and refract through the layers. This is the nacre version, the beautiful mother-of-pearl appearance we associate with pearls.
The calcite version doesn’t have the same light bending properties so it lacks the iridescence of the aragonite. It is dense, like thick porcelain.
The calcite version doesn’t have the same light bending properties so it lacks the iridescence of the aragonite. It is dense, like thick porcelain.
The best of these pearls have a shimmering effect known as flame structure.
The best of these pearls have a shimmering effect known as flame structure.
Just about any shelled mollusc is capable of producing a pearl of some sort, but the majority are of the non-nacreous kind. Some of the most common are produced by conches, scallops, Melo Melo and giant clams.
Conch (konk) pearls are produce by a large marine snail, the queen conch. The pearls are usually ovoid and small, ranging from white to a vibrant pink colour.
Scallop pearls are found in a species native to the coast of Baja, California. Fairly new to the market, they vary in size and shape. The colours range from cream to salmon or mauve with a semi-metallic sheen on the mosaic like patterns.
Some of the hardest pearls to find come from the marine baler snail, known as Melo Melo. The pearls from this mollusc are round, smooth and can be quite large.
Some of the largest pearls in the world are produced by the Giant Clam. These pearls are perfect examples of the difference between the nacreous and non-nacreous varieties. Thick, dense and white, it lacks the layers of light and colour and is mono-chromatic.
Nacreous Pearls
Akoya
Akoya pearls have been grown off the coast of Japan for almost a century. That classic strand of white round pearls that everyone knows and loves? Those are probably akoya pearls.
Tahitian
Tahitian pearls are the only naturally dark pearls. They come in many different colours, but they are often referred to as black Tahitian pearls. Round pearls of this type are rare; they are more common in shapes such as drops, ovals or baroques.
South Sea
The largest saltwater pearls grown today are South Sea pearls grown in Australia, the Philippines and Indonesia. They range in colour from white to gold. Like the Tahitian, round pearls are rare, while the drops, baroques and ovals are more common and equally valued.
Freshwater
FWP range from round to free-form baroques. They come in white and pastel colours and generally have a softer lustre than the akoya pearls. They are definitely the most affordable of the pearls, and they offer the widest range of options.
Pearl Grading
There is no agreed upon standard of grading for pearls, every company sets its own scale for quality. Some of the common traits that are looked for in gem quality pearls are lustre, shape, defects in the surface and colour.
Imitation Pearls
Imitation pearls are often made by dipping a glass bead into a solution made from fish scales. The coating this produces is very thin and will likely to wear off. The Spanish island of Mallorca is famous for its imitation pearls, and the terms Mallorca Pearls or Majorica Pearls are frequently used to describe these counterfeits.
One way to tell if your pearls are real or fake is to rub them across your teeth. Fake pearls will glide across, while real pearls feel gritty.
One way to tell if your pearls are real or fake is to rub them across your teeth. Fake pearls will glide across, while real pearls feel gritty.
Caring for your Pearls
Pearls are the only organic gemstone, and they need some special care. Sun block, perfume, cosmetics, hairspray; all contain chemicals that can damage the delicate nacre and dull the lustre of a pearl. Even the natural acids in body oils and perspiration can cause damage. As a general rule, your pearls should be the last thing you put on (at least 30 minutes after applying personal care products) and the first thing you take off. To protect your pearls, wipe them with a damp cloth after you wear them. This will help remove those chemicals that can do damage. Pearls are a very soft gemstone, so keep them separated from harder jewellery items. A soft cloth pouch is ideal. Don’t store them in an airtight place like a zip lock bag; this will cause them to become brittle.
Pearls are a reminder that great things can come from humble beginnings. Who would think that the product of an irritation in the innards of a strange looking marine creature could end up as prized possessions of gods and rulers of nations?