Pearl Information

Pearl Grading

The value of a pearl is determined by the following factors:

Lustre

This is the glow or shine of the pearl. Excellent lustre gives you the sense that you are looking into the pearl and that it has an inner glow.

Surface

How clean or unblemished the surface of the pearl is.

Colour

Although a personal factor, some colours are more expensive than others by virtue of their rarity.

Shape

Also a personal factor but the round and tear drop shape are the most expensive.

Size

As with any gem, size is a factor in determining price. Although bigger does not mean better. It is worth noting that as yet there is no internationally agreed grading system. That is a set of numbers and letters that describe all the factors above on an agreed scale. So for example, if you are offered an A grade pearl, it is a meaningless description if the full scale is not know e.g. "A" may be the second lowest if the grading scale is B, A, AA, AAA, AAAA. Also what part of the pearl is the A describing - the lustre or surface. So be sure to enquire about the whole grading scale when discussing pearls with a seller.

What is a pearl?

Pearls have been around since the dinosaurs and were man's first precious gem. Long before gem stones could be cut and faceted, pearls were a revered symbol of status, wealth and power. Myths about their origin abounded from tears of the moon to dew drops caught by oysters at night.
Pearls are organic gems produced by pearl oysters, freshwater mussels and some other molluscs. All pearls are made of "nacre", a crystalline structure of calcium carbonate knows as argonite. It is the way this structure allows light to penetrate, reflect and refract that makes pearls such a unique and beautiful gem. A pearl oyster or mussel will coat any irritant that it cannot expel with aragonite to smooth away the irritation.

Today just about all pearls are "cultured". That is, man has introduced an irritant into the animal to stimulate their natural response of coating the irritant with nacre. Conversely a natural pearl is the same process but nature introduced the irritant. Contrary to popular belief is was hardly ever a grain of sand but rather parasites and other small water born animals that became trapped in the oyster or mussel that would produce a natural pearl.

Natural pearls are extremely rare and valuable and were the source of the world's pearls before the culturing process was commercially made successful in Japan in the early 1900's. To find a gem quality natural pearl the odds are about 1 in 5000 shell. That is a lot of dead animals for one pearl. Many "natural pearl" shell grounds were over fished into virtual extinction.