When choosing pearls, there are 5 basic factors to consider; lustre, size, colour, surface, and shape.
The lustre of a pearl is the most important factor in determining its value which in turn impacts the value of the pearl. The lustre of a pearl measures its iridescence as opposed to the sparkling brilliance of a diamond.
Pearls increase in value with size. Pearls can range in size from 2-3mm to 20mm depending on the type of pearl. The combination of size and lustre determines the value of the pearl.
The colour of a pearl has no impact on its quality but it does affect the beauty as perceived by each individual. The major classifications of colours include white, cream, pink, gold, silver, and black although some pearls will have a secondary colour around the outside of the pearl- usually a green, blue, or pink.
Since all pearls are created in nature, even cultured ones, it is difficult to find them free from blemishes on the surface. These blemishes are what make each pearl unique. If found, a flawless surface will significantly increase the value of the pearl.
The scarcest of pearls are perfectly round- driving up the price of the pearl. Pearls are often found in the more common shapes of round, semi-round (mabe), circled, button, drop, oval, baroque, and semi-baroque.
In order to protect the beauty of your pearls, protect them from household chemicals including makeup, perfume, and hairspray. These chemicals can dull the lustre of a pearl and eventually cause spots or blemishes. As a general rule, pearls should be the last thing put on before going out for the evening and the first thing to come off when returning home. This will protect them from makeup and perfume.
The natural oils produced by the human body helps to keep pearls lustrous so it is best to wear them often. Before storing, pearls should be wiped clean with a soft cloth and should always be stored separately from other pieces of jewellery made of metals or gemstones which can scratch or dull the surface of pearls.