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Topaz is a silicate mineral made of aluminum and fluorine with the chemical formula Al 2 Si O 4 (F, OH) 2.It is used as a gemstone in jewelry and other adornments. Common topaz in its natural state is colorless, though trace element impurities can make it pale blue or golden brown to yellow-orange. [7]
The American Golden Topaz, housed in the National Museum of Natural History, Washington D.C.. The American Golden Topaz, a 172-faceted topaz weighing 22,892.5 carats (4.57850 kg; 10.0939 lb), is the largest cut yellow topaz in the world, and one of the largest faceted gems of any type in the world. [1]
The topaz in the Field Museum (2009) The Chalmer's Topaz is a topaz gem weighing 5,899.5- carats located in Chicago, Illinois ' Grainger Hall of Gems, in the Field Museum of Natural History . It was named for former Field Museum trustee William J. Chalmers and his wife Joan Chalmers, who established a fund used to purchase gemstones for the ...
A number of individual gemstones are famous in their own right, ... with a weight of 1,404.49 carats ... a 5,899.5-carat (1.17990 kg) cut topaz. Tsavorite
After paying $150,000 for the raw stones, Kogen has transformed them into exquisite rubies worth an estimated $530,000 in the marketplace. Learn more about Don. Show comments.
Main jade producing countries. Jade is an umbrella term for two different types of decorative rocks used for jewelry or ornaments.Jade is often referred to by either of two different silicate mineral names: nephrite (a silicate of calcium and magnesium in the amphibole group of minerals), or jadeite (a silicate of sodium and aluminum in the pyroxene group of minerals). [1]
Another technique first applied to quartz and topaz has also been adapted to cubic zirconia: An iridescent effect created by vacuum-sputtering onto finished stones an extremely thin layer of a precious metal (typically gold), or certain metal oxides, metal nitrides, or other coatings. [14] This material is marketed as "mystic" by many dealers.
The stone remains widely used in the United Kingdom and Ireland for human body weight: in those countries people may commonly be said to weigh, e.g., "11 stone 4" (11 stones and 4 pounds), rather than "72 kilograms" as in most of the other countries, or "158 pounds", the conventional way of expressing the same weight in the US and in Canada. [38]