Pearl Pearls are products of bivalve mollusks (mainly oysters and mussels). They are built up of nacre (mother-of-pearl), which is mainly calcium carbonate in the form of aragonite crystals, and an organic horn substance known as conchiolin that binds the microcrystals concentrically around an irritant. Although pearls are not especially hard, only about 2.5 to 4.5 on the Mohs scale, they are extraordinarily compact and very difficult to crush.
The typical pearly luster is produced by the overlapping platelets of aragonite and film of conchiolin nearest to the pearl surface. The color of pearl varies with the type of mollusk and the water, and is dependent on the color of the upper conchiolin layer. Pearls may be natural (occurring without human intervention) or cultured; and they may occur in the ocean or in freshwater.
Certified Customer Reviews
Overall Rating -> 9
The opals I ordered are absolutely beautiful, very fiery and well-cut. The pictures online didn’t do them justice. Shipping did take longer than expected (I chose the standard option), but the gemstones I received were definitely worth the wait.
I have purchased gems from Gem Select twice a year, for more than a few years.Gem select is the best place to buy gems. The selection and presentation are genuine. What you see is what you get, keeping in mind the carat weight, and measurements they have listed. Never have I been disappointed with any gem I have received from them. Nan
GemSelect has a great selection of smaller cabochons. Many other retailers do not. Plus, the photo of the stone is the one you are purchasing. Shipping from Thailand is nearly as fast as from within the US. Stones are tightly and neatly packaged.