Topaz is a rare silicate mineral with a chemical composition of Al2SiO4(F,OH)2. It usually forms in fractures and cavities of igneous rocks such as pegmatite and rhyolite, late in their cooling history. It is also found as water-worn pebbles in stream sediments derived from those igneous rocks.
https://bitbillions.com/precious-topaz-the-silicate-mineral/
Thursday, October 6, 2016
Precious Topaz The Silicate Mineral
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment