Diamond, the hardest known natural material, is named from the Greek "adamas", meaning invincible. A diamond is a transparent crystal of tetrahedrally bonded carbon atoms. Diamond is famed not only for its exceptional hardness, but also for its high refractive index and high dispersion of visible light - the ability to split white light into its component colors.
Diamonds can occur in nearly any color, though yellow and brown are by far the most common. Diamonds with a detectable hue other than yellow or brown are known as colored diamonds. If the color is strong enough, a stone may be referred to as a fancy colored diamond by the trade. Colored diamonds contain impurities or structural defects that cause the coloration, while pure or nearly pure diamonds are transparent and colorless.
Approximately half of the world's production of diamond comes from Central and Southern Africa, with other deposits found in Canada, India, Russia, Brazil, and Australia.
全体の評価 -> 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.