There are many gemstones and biogenic gem materials mentioned ... turquoise, diamond, agate, lapis lazuli, crystal, coral, pearl, peridot, ruby, and onyx. There are several important mentions ...
Today, tricks of the trade among some glitz and glamor: diamonds, jewelry and gemstones. The trading floor of the Pacific Stock Exchange, once just across the freeway from the Marketplace ...
The gem corundum is related to “dikes” of amphibolitic rocks that belong to the Paleoproterozoic Usagaran Belt. Based on crystal morphology, Winza corundum is subdivided into two types: ...
Timothy Poston. Photo by Rex Guo. Deciding how to cut a gemstone is inevitably one of the most difficult decisions when transforming a piece of rough into a fine faceted gem. The three main factors to ...