Prasiolite Explained

Prasiolite
Category:Oxide mineral
Boxbgcolor:
  1. 9cdfb9
Color:Shades of green
Mohs:7 – lower in impure varieties[1]
Diaphaneity:Transparent to nearly opaque
Fracture:Conchoidal
Tenacity:Brittle
Refractive:1.544 to 1.553[2]
Cleavage:None
Gravity:2.65
System:Trigonal
Habit:Hexagonal prisms
Fluorescence:None
Birefringence:0.009[3]

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, 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 Canada.[4]

Most prasiolite sold is used in jewellery settings, where it can substitute for far more expensive precious gemstones.

Prasiolite is a rare stone in nature; artificial prasiolite is produced by heat treatment of amethyst.[4] Most amethyst will turn yellow or orange when heated, producing heat-treated amethysts which are often marketed as citrine, but some amethyst will turn green when treated. Currently, almost all prasiolite on the market results from a combination of heat treatment and ionizing radiation.[5]

Green quartz is sometimes incorrectly called green amethyst,[6] which is not an acceptable name for the material according to Federal Trade Commission Guidelines. Other names for green quartz include vermarine and lime citrine.[7]

The word prasiolite literally means "scallion green-colored stone" and is derived from Greek πράσον prason meaning "leek" and λίθος lithos meaning "stone". The mineral was given its name due to its green-colored appearance.

Natural prasiolite is a very light, translucent green. Darker green quartz is generally the result of artificial treatment.[8]

See also

External links

Notes and References

  1. Web site: Prasiolite gemstone information. www.gemdat.org. 19 April 2018.
  2. Book: Lazarelli . Blue Chart Gem Identification . 7 .
  3. Web site: PRASIOLITE the green variety of quartz (aka Green Amethyst). www.galleries.com. 19 April 2018.
  4. Web site: Prasiolite . quarzpage.de . 28 October 2009 . 28 November 2010.
  5. Web site: Mineral Spectroscopy Server . California Institute of Technology . 11 June 2012 . 10 December 2012.
  6. Web site: Green Amethyst . GemSelect . 10 December 2012.
  7. Web site: Green Quartz Meaning and Properties . n.d.. firemountaingems.com . 2021-10-21.
  8. Gems and Gemstones: Timeless Natural Beauty of the Mineral World By Lance Grande, Allison Augustyn, p.91