Editing Amethyst (section)

==Value==
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|align=left
|perrow=2
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|image1=2012 Tucson 22nd Street Show 18.JPG
|image2=2012 Tucson Gem & Mineral Show 85.JPG
|footer=Amethyst geodes displayed at the 2012 [[Tucson Gem & Mineral Show]]
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Until the 18th century, amethyst was included in the cardinal, or most valuable, gemstones (along with [[diamond]], [[sapphire]], [[ruby]], and [[emerald]]), but since the discovery of extensive deposits in locations such as Brazil, it has lost most of its value.<ref name=Geary-Whelen-2008/> It is now considered a semiprecious stone.<ref>
{{cite journal
 |last1=Souza   |first1=Tamires P. |last2=Watte  |first2=Guilherme
 |last3=Gusso   |first3=Alaíde M.  |last4=Souza  |first4=Rafaela
 |last5=Moreira |first5=José da S. |last6=Knorst |first6=Marli M.
 |date=June 2017
 |title=Silicosis prevalence and risk factors in semi-precious stone mining in Brazil
 |journal=[[American Journal of Industrial Medicine]]
 |volume=60 |issue=6 |pages=529–536
 |doi=10.1002/ajim.22719 |pmid=28514023
 |s2cid=24375063
}}
</ref>

Collectors look for depth of color, possibly with red flashes if cut conventionally.<ref name=CIBJO>
{{cite book
 |title=The Gemstone Book: Gemstones, organic substances, & artificial products — terminology & classification
 |year= 2011
 |publisher= The World Jewellery Confideration (CIBJO)
 |url= http://download.cibjo.org/CIBJO_Gemstone_Book_2011-1.pdf
 | access-date= 27 June 2012 | url-status= dead
 |archive-url= https://web.archive.org/web/20120812224254/http://download.cibjo.org/CIBJO_Gemstone_Book_2011-1.pdf
 | archive-date= 12 August 2012 |df= dmy-all
}}
</ref>
As amethyst is readily available in large structures, the value of the gem is not primarily defined by carat weight. This is different from most gemstones, since the carat weight typically exponentially increases the value of the stone. The biggest factor in the value of amethyst is the color displayed.<ref name=gemsociety>
{{cite web
 |title=Amethyst jewelry and gemstones information
 |publisher=[[International Gem Society]] (IGS)
 |url=http://www.gemsociety.org/article/amethyst-jewelry-and-gemstone-information/
 |via=gemsociety.org  |access-date=3 October 2014
}}
</ref>

The highest-grade amethyst (called ''deep Russian'') is exceptionally rare. When one is found, its value is dependent on the demand of collectors; however, the highest-grade sapphires or rubies are still orders of magnitude more expensive than amethyst.<ref name=WiseSecrets1/>