While pearl is more often than not a product from nature, it is difficult to control every pearl are as beautiful and colorful as we anticipate, therefore, people will use some artificial method to change or modify the appearance of pearls. Only by this way, the most beautiful sides of pearls can bring to us. This is very similiar to the process of a jeweler cutting a raw diamond rocket to get a perfect diamond. Pearl treatements include:
Remove, lighten (make whiter) or alter (from dark to light) color by means of chemical and/ or physical agents or light. This process can make the color look more even.
Remove organic residues from the surfaces of natural and cultured pearls following harvest.
This technique is applied to natural and cultured pearls to remove some surface blemishes and increase luster.
Spread an artificial layer of substance over the pearl surface or part of the surface. It aims to change pearls color or improve pearl luster. Good-quality pearls do not have to be coated to look lustrous.
If a pearl is partially hollow or has a loose nucleus, people will fill the void with an epoxy substance. That will make the pearls more solid and improve their durability. Fillings can be detected with x-radiographs.
When light color pearls are bombarded with gamma rays, the irradiated pearls will achieve an iridescent bluish or greenish gray color. This method work well on freshwater pearls and can be used with dyeing.
Oiling is also used to improve pearl luster.
Any color caused artificially by the application of a dye to pearls can be call dyeing. Dyeing is the most often used technique to get colorful pearls that people want. Dyed pearls are not fakes, but people can get them much easier than pearls of natural color. They fulfill people's desire of special fashion in different occasions while cost less. For their soared price, few people can afford natural black or golden pearl, treated pearl is undoubtedly a great invention to fit different tastes and trends.
Maybe you still want to know which is dyed and which is natural and make the final decision. There is some tests Shecy can provide to help:
- Price test
Some types of true color pearls are typically expensive, e.g. Tahitian pearl, Golden South Sea pearl, Akoya pearl with Rose overtone (Hanadama pearl). If the price is unbelievably low and the merchant doesn't own a special reason for this price. The pearls are probably treated.
- Size test
If a pearl's diameter is smaller than 9mm, and is marked as Tahitian pearl or Golden South Sea pearl, that must be false color. For almost all Tahitian and South Sea pearl, expect for their Keshi pearls, are larger than 9mm. Akoya oysters, on the other hand, can only produce a wide range of pearls below 9mm.
- Drilled-hole test
Look at the drilled hole of a pearl. If the nucleus looks dark and nacre inside looks white, the pearl is dyed. The other clue that indicates dyed pearl is dye concentrating around the drill hole or on some spot of pearl surface.
- Color test
Observe the pearl color carefully. Any of the following clues would indicate whether the pearl is dyed or not.
Dyed color can be dark to black, and without natural overtone.
As a creature of nature, The true color pearl differ from one to the other, if all the pearls in the piece look the exact same color, the pearls are dyed.
- Magnifier test
Examine the surface of the pearl with a magnifier or loupe. If the color in or around the blemishes is stronger and more intense than the rest of the pearl, this pearl is dyed.