Home » Minerals » Sillimanite

Sillimanite


Mineral Properties and Uses



Physical Properties of Sillimanite

Chemical Classification silicate
Color colorless, white, yellow, brown, blue, green
Streak colorless
Luster vitreous
Diaphaneity transparent to translucent
Cleavage perfect
Mohs Hardness 6.5 to 7.5
Specific Gravity 3.2 to 3.3
Diagnostic Properties slender crystals, fibrous habit
Chemical Composition Al2SiO5
Crystal System orthorhombic
Uses no significant commercial use


Sillimanite with magnetite
Sillimanite with magnetite from Benson Mines, New York. Specimen is approximately 4 inches (10 centimeters) across.


Sillimanite
Sillimanite from Williamstown, South Australia. Specimen is approximately 4 inches (10 centimeters) across.



Find it on Geology.com




More from Geology.com


Diamonds from Coal
Biggest Misconception: Lots of people think that diamonds form from coal. Not True!
Sliding Rocks
Sliding Rocks Mystery: What causes these rocks to slide across a Death Valley playa?
gem photos
100+ Gems - Photos of over 100 beautiful gems ranging from the popular to the obscure.
Geology of Gems
Geology of Gems - The first comprehensive book on the geology of gem deposits.
Facts About Diamonds
Interesting Facts About Diamonds: You are a diamond expert if you know all of these!
Great Rift Valley
The East Africa Rift System: Learn about the complex East Africa Rift Valley system.
shale gas
Shale Gas is natural gas trapped within shale. It is a growing source of US supply.
Abandoned Mine Accidents
Abandoned Mine Accidents take 20 to 30 lives per year. Many can be prevented with education.


Sillimanite
Sillimanite with magnetite from Benson Mines, New York. Specimen is approximately 4 inches (10 centimeters) across.




Sillimanite
Sillimanite from Dillon, Montana. Specimen is approximately 4 inches (10 centimeters) across.


More Minerals
  Mohs Hardness Scale
  Kyanite
  Rock, Mineral and Fossil Collections.
  Calcite
  Minerals
  Topaz
  Diamond
  Corundum






© 2005-2016 Geology.com. All Rights Reserved.
Images, code, and content on this website are property of Geology.com and are protected by copyright law.
Geology.com does not grant permission for any use, republication, or redistribution.
Images, code and content owned by others are marked on the pages where they appear.