This 5 criteria including lustre, surface, colour, shape and size of pearl, these various criteria will be explored in detail in the guide below:
Lustre is considered as the most important and above all the others in a pearl, we can call it the soul of pearl. Luster is the intensity of light reflected and refracted from the pearl. Good lustre is when you look into a pearl and see a sharp reflection of yourself. In ebay, you should see a reflection of seller's camera.
As pearl is a living material, slight imperfections is unavoidable. Even the the most valuable grade pearl, a flawless surface is extremely rare. the flaw we find are blemishes. Jeweller usually use pearl with small blemishes as earrings.
Every pearl reflect pearl in different way, on surface or within the nacre or you might find that the pearl contain both reflect way. From our picture 1, you would find that black colour on the surface and peacock overtone within the nacre. The overtone colour is quite difficult to notice from the picture in ebay, as the picture quality is reduced to improve the loading speed. We suggest that you can ask seller before purchase, if you prefer a specific overtone colour, such as white colour with pink overtone.
The main categories of freshwater pearl shapes are nearly round, drop, oval, button, baroque, drop. Sometime you would find cross, biwa shaped pearl available in ebay, these shape of pearl are cultured under new method. The value is usually higher than main categories of freshwater pearl shape. A product of nature, all pearl are individual and unique.
Needless to say, the larger the pearl the greater its value