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Roger Weller, geology instructor
Chemical Group: silicate (plagioclase feldspar)
Chemical Formula: NaAlSi3O8 Albite is the sodium end member of the plagioclase feldspars.
Albite ranges from 90% to 100% NaAlSi3O8 and 10% to 0% CaAl2Si2O8.
Color: white; sometimes, pale blue, pale gray, pale red, pale green or green
Streak: uncolored Luster: vitreous, pearly Tenacity: brittle
Hardness: 6 to 6.5
Specific Gravity: 2.60 to 2.62
Fracture: uneven to conchoidal Transparency: translucent to transparent
Cleavage: (001) perfect and (010) slightly less
Crystal Forms: Triclinic
Crystals often tabular; sometimes elongated.
Commonly shows polysynthetic (plagioclase) twinning.
Mineral habits: massive, granular, lamellar (with curved surfaces)
Mineral Associations: found in granite, syenite, diorite
Identifying Characteristics: white color, plagioclase twinning
Occurrences: Maine, New Hampshire, Connecticut, Massachusetts, New York, Colorado
Toxicity: when-swallowed- moderate when inhaled- high
Additional Information: The name albite comes from albus, meaning white.