Spodumene

"Kunzite" redirects here. For the Sailor Moon character, see Shitennou.

Spodumene
An almost colourless kunzite crystal (upper left), a cut pale pink kunzite (upper right) and a greenish hiddenite crystal (below)
General
Category	Mineral
Chemical formula	lithium aluminium silicate, LiAl(SiO3)2
Identification
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Color	Highly variable: white, colorless, gray, pink, lilac, violet, yellow and green
Crystal habit	prismatic, generally flattened and elongated
Crystal system	monoclinic; 2/m
Cleavage	Perfect prismatic, two directions at nearly 90°
Fracture	Sub-conchoidal
Mohs Scale hardness	6.5 - 7
Luster	Vitreous
Refractive index	1.66-1.68
Pleochroism	Strong in kunzite: pink, colourless; hiddenite: yellow-green, blue-green
Streak	white
Specific gravity	3.17-3.19
	{{{density}}}
Fusibility	3.5
Solubility	insoluble
Other Characteristics	Tenebrescence, chatoyancy, kunzite often fluorescent under UV

Spodumene is a pyroxene mineral consisting of lithium aluminium inosilicate - LiAl(SiO₃)₂ - and is a source of lithium. It occurs as colourless to yellowish, purplish or lilac kunzite (see below), yellowish-green or emerald-green hiddenite, prismatic crystals, often of great size. Single crystals over 10 m in size are reported from the Black Hills of South Dakota.

Crystals form in the monoclinic system and are typically heavily striated parallel to the principal axis. Crystal faces are often etched and pitted with triangular markings.

Spodumene is derived from the Greek, meaning "burnt to ashes," owing to the opaque, ash-grey appearance of material refined for use in industry.

Spodumene occurs in lithium rich granites and pegmatites. Transparent material has long been used as a gemstone with varieties kunzite and hiddenite noted for their strong pleochroism. Source localities include Brazil, Madagascar, USA (North Carolina, California), Afghanistan, and Pakistan.

Economic Importance

Spodumene is an important source of lithium for use in industrial ceramics, mobile phone and automotive batteries, medicine and as a fluxing agent. Lithium is extracted from spodumene by fusing in acid.

World production of lithium via spodumene is arround 80,000 metric tonnes per annum, primarily from the Greenbushes pegmatite of Western Australia, and some Chinese and Chilean sources. Spodumene is becoming less important a source of lithium due to the emergence of alkaline brine lake sources in China and Argentina, which produce lithium carbonate and lithium hydroxide directly.

Kunzite

Kunzite

Kunzite is a pink to lilac colored gemstone, a variety of spodumene with the colour coming from minor to trace amounts of manganese. Some (but not all) kunzite used for gemstones has been heated to enhance its colour. It was named in honor of New York mineralogist and gemologist George Frederick Kunz. It has been found in Brazil, USA, Canada, CIS, Mexico, Sweden, Western Australia, Afghanistan and Pakistan. <br=clear all>

References

ISBN links support NWE through referral fees

• Anthony, John W., Bideaux, Richard A., Bladh, Kenneth W., and Nichols, Monte C. (1990): Handbook of Mineralogy: Mineral Data Publishing, Tucson, Arizona
• Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., ISBN 0-471-80580-7
• Kunz, George Frederick (1892) Gems and Precious Stones of North America. The Scientific Publishing Company, New York NY
• Palache, C., Davidson, S. C., and Goranson, E.A. (1930) The Hiddenite deposit in Alexander County, N.Carolina. American Mineralogist Vol 15 No. 8 p. 280
• Webster, R. (2000). Gems: Their sources, descriptions and identification (5th ed.), pp. 186-190. Great Britain: Butterworth-Heinemann.
• Webmineral
• Mindat.org

See also

• List of minerals

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