from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A potassium aluminum silicate mineral, KAl2(AlSi3O10)(OH)2, the most common form of mica, which ranges from colorless or pale yellow to gray and brown, has a pearly luster, and is used as an insulator. Also called white mica.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A pale brown mineral of the mica group, being a basic potassium aluminosilicate with the chemical formula KAl2(Si3Al)O10(OH,F)2; used as an electrical insulator etc.
Muscovy glass, its former name + -ite1.(American Heritage® Dictionary of the English Language, Fourth Edition)
In 1850 from Muscovy glass + -ite, from the province Muscovy in Russia. Named by James Dwight Dana. (Wiktionary)