What is Petalite gemstone?

Petalite, also known as castorite, is a lithium aluminium phyllosilicate mineral LiAlSi4O10, crystallizing in the monoclinic system. Petalite occurs as colorless, pink, 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, and is converted to spodumene and quartz by heating to ~500 °C and under 3 kbar of pressure in the presence of a dense hydrous alkali borosilicate fluid with a minor carbonate component.[6] Petalite (and secondary spodumen formed from it) is lower in iron than primary spodumen making it a more useful source of lithium in e.g. the production of glass. The colorless varieties are often used as gemstones.

Discovery and occurrence

Petalite from Paprok, Nuristan Province, Afghanistan (size: 7.3 x 2.9 x 2.4 cm)
Discovered in 1800, by Brazilian naturalist and statesman Jose Bonifacio de Andrada e Silva. Type locality: Utö Island, Haninge, Stockholm, Sweden. The name is derived from the Greek word petalon, which means leaf (perfect cleavage).[4][7][8]

Economic deposits of petalite are found near Kalgoorlie, Western Australia; Aracuai, Minas Gerais, Brazil; Karibib, Namibia; Manitoba, Canada; and Bikita, Zimbabwe.

The first important economic application for petalite was as a raw material for the glass-ceramic cooking ware CorningWare.[citation needed] It has been used as a raw material for ceramic glazes.

References
"Petalite". Digital Fire. Retrieved 23 October 2011.
Handbook of Mineralogy
Webmineral
Mindat
*Hurlbut, Cornelius S. and Klein, Cornelis, 1985, Manual of Mineralogy, Wiley, 20th ed., pp. 459–460 ISBN 0-471-80580-7
Deer, W. A. (2004). Framework silicates: silica minerals, feldspathoids and the zeolites (2. ed.). London: Geological Soc. p. 296. ISBN 978-1-86239-144-4.
D'Andraba (1800). "Des caractères et des propriétés de plusieurs nouveaux minérauxde Suède et de Norwège , avec quelques observations chimiques faites sur ces substances". Journal de Physique, de Chimie, d'Histoire Naturelle, et des Arts. 51: 239.
Sowerby, James (1811). Exotic mineralogy: Or, Coloured figures of foreign minerals: As a supplement to British mineralogy.
External links
Media related to Petalite at Wikimedia Commons
"Petalite" . Encyclopædia Britannica. 21 (11th ed.). 1911.