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In 1986, California named benitoite as its state gemstone, a form of the mineral barium titanium silicate that is unique to the Golden State and only found in gem quality in San Benito County. [ 80 ] ^ Colorado is the only state whose geological symbols reflect the national flag's colors: red (rhodochrosite), white (yule marble), and blue ...
Download as PDF; Printable version; In other projects ... There are a number of organic materials used as gems, including: Amber; ... This page was last edited on 24 ...
Gemstone. 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 ...
Diamond[ a] is a gemstone formed by cutting a raw diamond. Diamonds are one of the best-known and most sought-after gems, and they have been used as decorative items since ancient times. The hardness of diamond and its high dispersion of light —giving the diamond its characteristic "fire"—make it useful for industrial applications and ...
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]
New York City. , New York. , United States. Website. www .gemscience .net. Gemological Science International, or GSI, is an independent gemological organization that is one of the largest gemological entities in the world, with offices in four continents. [1] [2] [3]
Emerald is a gemstone and a variety of the mineral beryl (Be 3 Al 2 (SiO 3) 6) colored green by trace amounts of chromium or sometimes vanadium. [2] Beryl has a hardness of 7.5–8 on the Mohs scale. [2] Most emeralds have many inclusions, [3] so their toughness (resistance to breakage) is classified as generally poor. Emerald is a cyclosilicate.
The first theme is using legendary luminous gems to illuminate buildings, for navigation lights on ships, or sometimes as guiding lights for lost persons (Ball 1938: 498–500). In India, the earliest country in which fine gemstones were known, belief in luminous gems dates back some twenty-five centuries.