Pearl Shapes and Types
                              from The Pearl Market

Pearl Shapes and Types

If you have read the section How Pearls are Formed you will know that pearls develop into a variety of shapes. Traditionally, round pearls command the highest prices but very few pearls are perfect spheres.

It is always worth remembering that wild natural pearls were rarely round and that differently shaped pearls can give you a lot of pearl at a much lower cost.

ROUND PEARLS

Round pearls are rarely perfect spheres unless they are of gem quality or imitation. The longer the pearl remains within the oyster or mussel, the more chance there is of it developing a different shape. Contrary to the images portrayed in films very large round pearls are uncommon - and very expensive. Even seawater pearls, which have a round shell bead as their nucleus, have a hard time keeping their shape as they grow. Increasing the size of bead increases the mortality rate of the oyster. Many of the largest, most beautiful pearls come from the South Seas.

OFF-ROUND PEARLS

The term off-round is used to describe pearls which are 'roundish' to the eye but have a slightly oval or flattened shape. They can still have excellent qualities in terms of lustre or lack of blemish but being off-round makes them less expensive. Before the cultured pearl industry began in the early 1900's most natural wild pearls were off-round or baroque (a general term for an irregular shape). Off round pearls can provide excellent value for money.

OVAL PEARLS

Oval pearls are sometimes also known as rice pearls although this is a slightly misleading term. It comes from the early days of Chinese freshwater pearl production when large numbers of low quality pearls came onto the market and were derided as 'rice-crispies' after the cereal. Today, Chinese freshwater pearls can compete in quality with the world's best. Oval pearls come in a variety of sizes and colours. Sometimes they are formed when two pearls growing close to one another in the same mollusc join together.

BUTTON PEARLS

Many people think of an oyster or mussel producing one pearl. In fact a mollusc may create over a dozen pearls depending on how it is seeded. Many of these are button pearls, so-called because of their distinctive shape - round on one side and flat on the other. Though unrelated to button pearls, America once had a thriving freshwater pearl industry producing mother-of-pearl buttons for coats and jackets. The industry died with the development of plastic and American freshwater pearls are now mainly used for domestic consumption or for export to Japan for nucleating seawater pearls.

BIWA PEARLS

The term 'Biwa' derives from Lake Biwa - a large freshwater lake near Kyoto in Japan. This was once the focus of the Japanese freshwater pearl industry. In the 1980's pearl production there virtually ceased due to industrial pollution. Biwa became a generic name for all freshwater pearls regardless of their shape. Technically it is incorrect to call pearls Biwa pearls (like French fries or English muffins) unless they actually come from Lake Biwa. We use the term simply to identify the unique shape of these particular pearls.

PEARL COLOURS

Pearls come in a variety of natural colours - shades of white, cream and pink being the most common and most popular. Colour depends on many factors. Some molluscs (there are many varieties and hybrids of oyster and mussel) have a tendency to produce certain colours. Diet and water quality and content (the presence of chemicals or pollutants) also play a part. Sometimes pearls are dyed or irradiated to achieve a particular colour. Black pearls (eg. the famous Tahitian black pearl) are often not black at all but contain shades of grey, blue and green.