珍珠 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.
综合评分 -> 9
GemSelect has a wide selection of gems with photos of the actual gem that you will be purchasing, not some stock photo. Once a purchase is made, you can print out a certificate of authenticity. You know you are getting the real thing. The pricing is competitive. Their website also has useful information about gems.The website is easy to use. I have made multiple purchases with GemSelect, and I will be back again!
My experiences with Gemselect have always been quite satisfactory. The items are accurately photographed, a detailed description and provenance provided and the compare feature helps customers select the best gem for their needs. I have often recommended this source and will continue to do so.
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I frequently check the GemSelect website for a variety of gems. I've been very satisfied with the selection and quality of the top rated gems. All of the purchases I've made have turned out beautiful pieces of jewelry.