Roger Weller, geology instructor
[email protected]
copyright 2007-R.Weller
Mineral
Information on:
andalusite
Chemical Group: silicate
Chemical Formula: Al2SiO5
Color: variable, white, gray rose-red, brown
Luster: vitreous to dull
Transparency: translucent
Hardness: 7.5
Specific Gravity: 3.15
Streak: white
Cleavage: one direction
Crystal Forms and
Habits: Orthorhombic system
Crystals are commonly prismatic with nearly square cross sections.
Crystals are often rounded.
Cross sections of crystals have carbonaceous inclusions
in a cross-patter: variety chiastolite.
Mineral Associations: found in contact metamorphic shales
Identifying Characteristics:
Uses: Used in the manufacture of spark plugs.
USA occurrences:
California
Dalton, Madera County
White Mountain, Mono County
Massachusetts
Lancaster
New Hampshire
Mt. washington
WORLD-WIDE occurrences:
South Africa
China
Brazil
Arrasuai, Minas Gerais
Australia
Broken Hill
Toxicity: when-swallowed- low
when inhaled- high
Additional Information: