Four main types of pearls
Pearls, romantically referred to as teardrops from the moon, have long been revered for their beauty and unique entrance into the world. They are formed by molluscs when an irritant gets stuck in their shells. Layer upon layer of a fluid called nacre are then formed around the irritant as a defence mechanism by the creature. The layers of nacre are what the beautiful lustrous pearls are made of. They are the oldest known gems and, for a time, were considered among the most valuable before they could be cultured or farmed. There are four main types of pearls that come in a variety of shapes, colours, and sizes.
Freshwater pearls are the most common and least expensive. They are cultured in freshwater lakes and ponds, hence the name, and are generally easy to find. Freshwater pearls come in the widest range of shapes and colours of all the pearl types.
While perfectly round freshwater pearls do exist, off-round shapes are more common and look beautiful and unique in jewellery. Pink, white, and other pastel colours are the most common occurring naturally, but they can be dyed any colour for optimal jewellery making.
Deemed the classic pearl, these come to mind when you think about the perfect pearl. They are considered an upgrade from freshwater pearls in quality and roundness. Akoya pearls also come in a variety of neutral colours, but tend to be white.
They are small and round, typically ranging from 5-9mm, and take one to two years to develop. Akoya pearls are the most common among jewellery buyers and make beautiful necklaces, bracelets, and earrings.
Tahitian black pearls
Although called black, Tahitian black pearls actually come in a range of dark, natural colours. Most common are greens, blues, browns, and greys. No colour is considered better than another; they are all equal in value. The most popular colour amongst buyers is known as green peacock.
Tahitian black pearls are much bigger and more expensive than Akoya pearls. The price is partly due to the difficulty in creating a perfect strand because of the colour range.
South Sea pearls
There are really two types of South Sea pearls: white and golden. They are the biggest and most valuable of all pearl types. It is typical for a South Sea pearl to be up to 17mm, but much bigger white South Sea pearls have been found.
These pearls take two to four years to develop and are usually not perfectly round. Perfectly matched strands are rare and can cost up to £24,500 ($300,000 US).
Golden South Sea pearls are considered the most valuable among all pearls. The value increases with natural golden colour; the deeper the gold, the more valuable.