PEARL : This is an Organic Gemstone, formed by accident, without human intervention. It is formed inside a Pearl Oyster. One of the most valuable gems in antiquity, pearls are highly valued. They are evaluated according to size, colour, lustre, regularity of form, compactness. In case of a number of pearls in a piece of jewellery, much depends on their uniformity of colour or, at any rate, how well matched they are. A string of pearls of equal diameter is worth much more than one consisting of pearls of graduated diameters because numerous pearls of a uniform size are harder to find. Even a pair of matching pearls is worth more than double the price of a single pearl. Pearls have a pearly lustre.

Appearance : Most pearls used in jewellery are roughly spherical, and this is the most suitable for ordinary necklaces. Pearls may be somewhat irregular in shape. The colour varies from white with a hint of gray to white with a yellow tinge, but can also be silvery gray or more noticeably yellow. Pearls have a pearly lustre.

Occurrence : Most Pearls harvested today come from China, Mississippi, South Sea Islands, Strait of Mannar, Japan. Pearls from Persian Gulf have now exhausted.

Substitutes : Plastic or Glass coated and dyed.

Chemical Composition : CALCIUM CARBONATE.