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Mineral Properties and Uses

Physical Properties of Pyrophyllite

Chemical Classification silicate
Color white, pale blue, yellow, grayish green, brownish green
Streak white
Luster pearly to greasy
Diaphaneity translucent
Cleavage perfect
Mohs Hardness 1 to 2
Specific Gravity 2.7 to 2.9
Diagnostic Properties cleavage, greasy feel
Chemical Composition Al2Si4O10(OH)2
Crystal System monoclinic
Uses ceramics, refractory materials

Layering of pyrophyllite from Moore County, North Carolina. Specimen is approximately 3/4 inch (1.9 centimeters) thick.

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Pyrophyllite from Moore County, North Carolina. Specimen is approximately 4 inches (10 centimeters) across.

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