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Gemstones of the World revised 5th edition, 2013 by Walter Schumann ISBN 978-1454909538 Smithsonian Handbook: Gemstones by Cally Hall, 2nd ed. 2002 ISBN 978-0789489852 hide
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 ...
This is a list of minerals which have Wikipedia articles. ... Sapphire (gem corundum of any color except red, especially blue varieties) Sard ...
However, generally speaking, soft minerals are not typically used as gemstones by virtue of their brittleness and lack of durability. [ 7 ] Found all over the world, the industry of coloured gemstones (i.e. anything other than diamonds) is currently estimated at US$1.55 billion as of 2023 and is projected to steadily increase to a value of US$4 ...
Gemstones are basically categorized based on their crystal structure, specific gravity, refractive index, and other optical properties, such as pleochroism. The physical property of "hardness" is defined by the irregular Mohs scale of mineral hardness. Gemologists study these factors while valuing or appraising cut and polished gemstones.
Bahia Emerald [2]; Carolina Emperor, [3] [4] 310 carats uncut, 64.8 carats cut; discovered in the United States in 2009, resides in the North Carolina Museum of Natural Sciences, Raleigh, NC, US
Avid rock collectors often use their specimens to learn about gemstones, petrology, mineralogy and geology as well as skills in the identification and classifying of specimen rocks, and preparing them for display. The hobby can lead naturally into lapidary projects, and also the cutting, polishing, and mounting of gemstones and minerals. The ...
This list includes those recognised minerals beginning with the letter E.The International Mineralogical Association is the international group that recognises new minerals and new mineral names; however, minerals discovered before 1959 did not go through the official naming procedure, although some minerals published previously have been either confirmed or discredited since that date.