Search results
Results from the WOW.Com Content Network
Amethyst is a violet variety of quartz.The name comes from the Koine Greek αμέθυστος amethystos from α - a-, "not" and μεθύσκω (Ancient Greek) methysko / μεθώ metho (Modern Greek), "intoxicate", a reference to the belief that the stone protected its owner from drunkenness. [1]
Group of precious and semiprecious stones—both uncut and faceted—including (clockwise from top left) diamond, uncut synthetic sapphire, ruby, uncut emerald, and amethyst crystal cluster. A gemstone (also called a fine gem , jewel , precious stone , semiprecious stone , or simply gem ) is a piece of mineral crystal which, when cut or ...
A ruby is a pink to blood-red colored gemstone, a variety of the mineral corundum (aluminium oxide).Other varieties of gem-quality corundum are called sapphires.Ruby is one of the traditional cardinal gems, together with amethyst, sapphire, emerald, and diamond. [1]
There are a limited number of commercially available diamond mines currently operating in the world, with the 50 largest mines accounting for approximately 90% of global supply. [1] Diamonds are also mined alluvially over disperse areas, where diamonds have been eroded out of the ground, deposited, and concentrated by water or weather action.
Prasiolite (also known as green quartz, green amethyst or vermarine) is a green variety of quartz. Since 1950, almost all natural prasiolite has come from a small Brazilian mine, [citation needed] but it has also been mined in the Lower Silesia region of Poland. Naturally occurring prasiolite has also been found in the Thunder Bay area of ...
Ametrine, also known as trystine, golden amethyst, or by the trade name bolivianite, is a variety of quartz with alternating zones of purple and yellow-orange coloration. Its name is a portmanteau of amethyst and citrine. While ametrine is commonly referred to as a combination of these two quartz varieties, some sources claim this is not ...
Painite is a very rare borate mineral.It was first found in Myanmar by British mineralogist and gem dealer Arthur C.D. Pain who misidentified it as ruby, until it was discovered as a new gemstone in the 1950s.
Diamond and graphite provide examples of cleavage. Each is composed solely of a single element, carbon. In diamond, each carbon atom is bonded to four others in a tetrahedral pattern with short covalent bonds. The planes of weakness (cleavage planes) in a diamond are in four directions, following the faces of the octahedron.