- align=center bgcolor="#9966FF"	Petalite		- align=center	Image needed		- align=center bgcolor="#9966FF"	General		-	Category	Mineral	-	Chemical formula	lithium aluminium tectosilicate mineral LiAlSi4O10	- align="center" bgcolor="#9966FF"	Identification		-	Color	colorless, grey, yellow, yellow grey, to white	-	Crystal habit	tabular prismatic crystals and columnar masses	-	Crystal system	monoclinic 2/m.	-	Cleavage	Perfect in one plane.	-	Fracture	Subconchoidal	-	Mohs Scale hardness	6 - 6.5	-	Luster	Vitreous, pearly on cleavages.	-	Refractive index	nα=1.504 nβ=1.510 nγ=1.516	-	Pleochroism	-	-	Streak	Colorless	-	Specific gravity	2.4	-	Fusibility	5	-	Solubility	Insoluble	-	Other	Fluorescent	- align="center" bgcolor="#9966FF"

Petalite, also known as Castorite is a lithium aluminium tectosilicate mineral LiAlSi₄O₁₀, crystallizing in the monoclinic system. Petalite is a member of the feldspathoid group. It occurs as colorless, grey, yellow, yellow grey, to white tabular crystals and columnar masses. Occurs in lithium-bearing pegmatites with spodumene, lepidolite, and tourmaline. Petalite is an important ore of lithium. The colorless varieties are often used as gemstones.

Discovered in 1800, type locality: Utö Island, Haninge, Stockholm, Sweden. The name is derived from Greek petalon for leaf.

See also: List of minerals

References

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• Hurlbut, Cornelius S.; Klein, Cornelis, 1985, Manual of Mineralogy, 20th ed., ISBN 0471805807
• Webmineral
• Mindat
• Neab.net

Lithium minerals | Tectosilicates

Petalite | Petaliet | Petalit