Formula: (Mn,Mg)5(SiO4)2(OH)2
Origin of name: for Paul H. Ribbe, American mineralogist of Virginia Polytechnical Institute and State University.
Crystal system: orthorhombic
Crystal class: 2/m 2/m 2/m
Twinning:
Unit cell: a = 10.732, b = 15.672, c = 4.811
Colour: pink
Diaphaneity: transparent
Luster: vitreous
Habit: granular crystals, 0.5 mm
Hardness: 5
Specific gravity: 3.90
Cleavage: none
Tenacity:
Streak: light pink
Synonyms/varieties:
Comments: dimorphous with alleghanyite
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