Definition of "cryolite" [cry•o•lite]

• An uncommon, white, vitreous natural fluoride of aluminum and sodium, Na3AlF6, nearly invisible in water in powdered form and used chiefly in the electrolytic recovery of aluminum. Also called Greenland spar. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "At the smelter, the aluminum oxide crystals are dissolved in a bath of something called cryolite (sodium aluminum fluoride) and zapped with enormous jolts of electricity (100,000 to 150,000 amps), which strips the oxygen from the aluminum."
• "It was at first manufactured from common clay, which contains about one-fourth its weight of aluminum, but in 1855 Rose announced to the scientific world that it could be obtained from a material called "cryolite," found in Greenland in large quantities, imported into Germany under the name of "mineral soda," and used as a washing soda and in the manufacture of soap."
• "At length he tried a stone from Greenland called "cryolite," which had already been used for making a kind of porcelain."