Petalite, also known as castorite, is a

lithium Lithium (from , , ) is a chemical element; it has chemical symbol, symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard temperature and pressure, standard conditions, it is the least dense metal and the ...

aluminum Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Mi ...

Li Al Si₄ O₁₀, crystallizing in the

monoclinic In crystallography, the monoclinic crystal system is one of the seven crystal systems. A crystal system is described by three Vector (geometric), vectors. In the monoclinic system, the crystal is described by vectors of unequal lengths, as in t ...

system. Petalite occurs as colorless, pink, grey, yellow, yellow grey, to white tabular crystals and columnar masses. It occurs in lithium-bearing pegmatites with spodumene, lepidolite, and

tourmaline Tourmaline ( ) is a crystalline silicate mineral, silicate mineral group in which boron is chemical compound, compounded with chemical element, elements such as aluminium, iron, magnesium, sodium, lithium, or potassium. This gemstone comes in a ...

. Petalite is an important ore of lithium, and is converted to spodumene and

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ...

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. Petalite (and secondary spodumene formed from it) is lower in iron than primary spodumene, making it a more useful source of lithium in, e.g., the production of glass. The colorless varieties are often used as

gemstone A gemstone (also called a fine gem, jewel, precious stone, semiprecious stone, or simply gem) is a piece of mineral crystal which, when cut or polished, is used to make jewellery, jewelry or other adornments. Certain Rock (geology), rocks (such ...

Discovery and occurrence

Petalite was discovered in 1800, by Brazilian naturalist and statesman Jose Bonifacio de Andrada e Silva. Type locality: Utö Island, Haninge,

Stockholm, Sweden Stockholm (; ) is the Capital city, capital and List of urban areas in Sweden by population, most populous city of Sweden, as well as the List of urban areas in the Nordic countries, largest urban area in the Nordic countries. Approximately ...

. The name is derived from the Greek word petalon, which means ''leaf'', alluding to its perfect cleavage. Economic deposits of petalite are found near Kalgoorlie,

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

; Aracuai,

Minas Gerais Minas Gerais () is one of the 27 federative units of Brazil, being the fourth largest state by area and the second largest in number of inhabitants with a population of 20,539,989 according to the 2022 Brazilian census, 2022 census. Located in ...

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

; Karibib,

Namibia Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the no ...

;

Manitoba Manitoba is a Provinces and territories of Canada, province of Canada at the Centre of Canada, longitudinal centre of the country. It is Canada's Population of Canada by province and territory, fifth-most populous province, with a population ...

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

; and Bikita,

Zimbabwe file:Zimbabwe, relief map.jpg, upright=1.22, Zimbabwe, relief map Zimbabwe, officially the Republic of Zimbabwe, is a landlocked country in Southeast Africa, between the Zambezi and Limpopo Rivers, bordered by South Africa to the south, Bots ...

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

References

External links

* * {{Lithium compounds Lithium minerals Monoclinic minerals Minerals in space group 13 Gemstones