Distinguishing Features
In 2206 BC, A Chinese historian wrote about pearls for the first time and recorded them as the most prized natural wonder.
In 1893, Kokichi Mikimoto successfully cultured a pearl in Japan.
In 1917, Pierre Cartier traded a double strand of natural pearls for a mansion on Fifth Avenue in New York City, 653 Fifth Avenue.
US birthstone for June, together with alexandrite and moonstone.
The Most Desirable Picks
The overall quality and value of pearls are size, shape, colour, lustre, surface quality, nacre quality, and—for jewellery with two or more pearls—matching. These are GIA's 7 Pearl Value Factors™. Depending on pearl type, one value factor might contribute more to a pearl's value than another.
Size:
Different pearl types have different size ranges. Within the normal size range of each type, when other value factors are equal, larger pearls are more valuable than smaller pearls because of their rarity.
Shape:
Pearls come in eight basic shapes: round, semi-round, button, drop, pear, oval, baroque, and circled. Perfectly spherical pearls and symmetrical drops are the most valued. Round is the most difficult shape to culture, making it the rarest cultured pearl shape and—if all other factors are equal—also generally the most valuable. There are exceptions, though. Well-formed pear, oval, or baroque (irregularly shaped) cultured pearls are also prized by pearl lovers.
Colour:
Natural and cultured pearls occur in a broad range of hues. There are warm hues like yellow, orange, and pink, and cool hues like blue, green, and violet. Pearls have a wide range of tones, from light to dark. Pearl colours tend to be muted, with a soft, subtle quality. Bodycolor is the pearl's dominant overall colour. Overtones in a pearl's lustre and the rainbow iridescence known as orient also add to the colour of a pearl. Consumer preferences, fashion trends, and cultural traditions influence the popularity of pearl colour from time to time, and the value of pearls is determined by supply and demand.
Lustre:
Lustre is the quality of reflections displayed by a pearl's surface. Sharper and deeper reflections are strong indications of high nacre quality.
· Excellent – Reflections appear bright and sharp
· Very Good – Reflections appear bright and near sharp
· Good – Reflections are bright but not sharp, and slightly hazy around the edges
· Fair – Reflections are weak and blurred
· Poor – Reflections are dim and diffused
Within a pearl type, when other value factors are equal, the higher the lustre, the more valuable the pearl.
Surface quality:
Most pearls never achieve perfection; a pearl with a flawless surface is extremely rare. Some might show abrasions that look like a series of scratches on the surface, a flattened section that doesn't affect its basic shape or an irregular ridge that looks like a crease or wrinkle. If surface characteristics are numerous or severe, they can affect the durability of the pearl and severely depress its value. Surface characteristics have less effect on the pearl's beauty and value if they are few or minor enough to be hidden by a drill hole or mounting.
Nacre quality:
Lustre and nacre quality are closely related. If the nucleus is visible under the nacre, or if the pearl has a dull, chalky appearance, you can assume that the nacre is thin. This affects the lustre as well as the durability of the pearl.
Matching:
The pearls should match in all the quality factors for most pearl strands, earrings, or other multiple-pearl jewellery.
Origins
Natural pearls were once more prevalent worldwide and prized by almost all cultures. They virtually disappeared from the mainstream jewellery market in the twentieth century due to pollution, over-fishing, and economic factors. Nowadays, they occasionally appear as antiques or estate in auctions. Fine natural pearls can command very high prices.
From the 1930s through the 1980s, pearl culturing diversified and spread to various countries worldwide. Each cultured pearl type has dominating farming regions.
1. Akoya:
Typical size: 6-8 mm, but some pearls can be as small as 2mm or as large as 11mm
Colour: Mostly white to cream bodycolour; other natural colours include yellow, grey, and blue.
Sources: Japan and China are the primary sources. Vietnam, Korea, Southeast Asia, Australia, the Red and Mediterranean seas, the Persian Gulf, the South and East African coast and the Caribbean also grow Akoya.
2. South Sea:
Typical size: 8 to 18 mm, most falling between 10 to 15 mm
Colour: The most common bodycolours are white, cream, and golden (dark brownish yellow, but they also exist in other colours.
Sources: Australia, Indonesia, and the Phillippines are leading sources. Myanmar and Thailand are also significant producers.
3. Tahitian:
Typical size: 8-17 mm; larger pearls exist in limited quantities
Colour: usually range from white to black; other colours include dark metallic greens and purples.
Sources: Cultivated primary around the islands of French Polynesia (the most familiar of which is Tahiti), and the Cook Island.
4. Freshwater:
Size and colour: Wide range of sizes, shapes and colours.
Sources: Pearls cultured in streams, rivers, and lakes, China and the US are the leading sources.
5. Keshi (Japanese for "poppyseed" ):
Pearls that form unintentionally in molluscs undergoing pearl cultivation.
6. Blister pearls:
Cultured or natural pearls that form over a solid core inside a freshwater or saltwater molluscs' shell. The side that faces the shell is flat and lacks nacre.
7. Mabe:
An assembled product consisting of a cultured blister pearl dome cemented to a backing made from mother of pearl shell. After harvesting, the nucleus is removed, and the hollow interior is usually filled with a material such as epoxy resin.
Most pearls are nacreous, whether natural or cultured. Other natural pearls do not share this concentric arrangement of aragonite crystals. Instead, their crystals are arranged in columns that are mostly perpendicular to the pearl's surface. These pearls are known as non-nacreous. Two best-known non-nacreous porcelaneous pearls are conch pearls and Melo pearls.
8. Conch Pearls:
Source: Produced by Queen conch, Strombus gigas found in the Caribbean Sea
Size: rarely spherical; most are oval or irregular in shape with lengthwise dimensions almost always under 10 mm.
Colour: Pink, particularly strong pink are most valuable.
9. Melo pearls:
Size: Usually large and spherical, but between 20 to 30 mm in diameter are not common.
Colour: Orange
Sources: Produced by sea snails live in Southeast Asia and Australian waters.
Conch pearls and Melo pearls may exhibit flame structure, an optical phenomenon created when intersecting groups of crystals interact with light, which increases their value.
Significant Pieces
Queen Mary's Lover's Knot Tiara
The Lover's Knot Tiara was commissioned for Queen Mary in 1913 from Britain's House of Garrard. Accordingly, it is also called Queen Mary's Lover's Knot Tiara. Queen Mary modelled her new tiara off of a tiara owned by her grandmother, Augusta, Duchess of Cambridge. The inspiration tiara passed to Queen Mary's aunt, Augusta, Grand Duchess of Mecklenburg-Strelitz. It consists of diamonds and a collection of 19 hanging pearls, all set in silver and gold. Later it was handed down to Queen Elizabeth. She then eventually gave it to her daughter-in-law, Princess Diana.
Through Diana, Lover's Knot became one of the most recognizable pieces of jewellery belonging to the British royal family. (Allegedly, the piece was so heavy that she used to get headaches after wearing it.) She famously paired it with a white, pearl-encrusted Catherine Walker ensemble while visiting Hong Kong in 1989. Upon her divorce from Prince Charles, the tiara was returned to Queen Elizabeth.
Kate Middleton first wore the tiara in December 2015 for that year's Diplomatic Reception.Since then, it's become the Duchess's formal headwear of choice.
Formation
A pearl is produced by a living organism, thus it is an organic gem. Natural pearl formation starts when a foreign object gets inside a pearl-bearing mollusc's shell and irritates its soft tissue, or mantle it forms without human assistance. In comparison, a cultured pearl formed as the result of human intervention in the process.
The mollusc tries to reduce the irritating effect by coating the foreign object with layers of smooth nacre, which is a crystallized form of calcium carbonate.
Nacre and mother of pearl have the same composition but are found in different places inside a pearl-bearing mollusc's shell.
Stability
Care and Cleaning
For routine care, wipe cultured pearls with a very soft, clean cloth after each wearing.
Avoid using hot water or scrubbing your jewellery with harsh or abrasive chemicals like chlorine or bleach, and avoid using ammonia-based cleaners.