All pearls are formed when a small object finds its way into a oyster and becomes an irritant. As a natural reaction the oyster coats it with a substance called nacre and it is the continual covering of this nacre which we call the pearl.

There are two types of pearls. Natural and cultivated. Natural pearls are those which nature has formed by itself. The irritant has gotten into the oyster through some crevasse or small opening and irritated the oyster to form the nacre covering.

A cultivated pearl is made by the deliberate insertion of a foreign substance, often another piece of shell, to the oyster and then nurturing it for a number of years until a pearl is made.

Whereas the natural pearl can be many different shapes and sizes and even colors, the cultivated pearl tends to be round or spherical in shape although coloring can be added to ensure the pearl is of a particular hue or color.

The discovery of how to make cultivated pearls changed the pearl industry for all time. Pearls became available to most people and not just to the select few due to their rarity.

This boosted the industry to a multi million dollar enterprise that flourishes around the world today.

Cultured pearls can be made virtually if not completely flawless and the oyster, during the pearl making process, is monitored and cared for in order to enable it to produce the best cultivated pearls.

Ti can also be done in bulk and this also brings the price for cultivated pearls down to an affordable price and pearls became accessible to large numbers of people around the world.

The advent of cultured pearls took most of the risk, and guesswork out of the pearl industry, allowing it to become stable and predictable, and fostering its rapid growth over the past 100 years. Today the cultured pearl industry has effectively replaced the natural pearl industry, turning the natural gems of old into collectors' pieces.

Apart from the obvious color, size and shape of natural pearls as against cultivated you can also tell the difference using x-rays to reveal the nucleus of the pearl.