Formula: (Fe,Mg)3Si4O10(OH)2
Origin of name: From locality; Minnesota
Crystal system: Triclinic
Crystal class: 1
Twinning:
Unit cell: a = 5.623, b = 9.419, c = 9.624, α = 85.21°, β = 95.64°, γ = 90°
Colour: Greenish gray, pale green
Diaphaneity: Translucent
Luster: Greasy to waxy or dull
Habit: Plates or needles, microscopic, disseminated or in compact aggregates, foliated, radial
Hardness: < 3
Specific gravity: 3.01
Cleavage: 1; {001} perfect
Tenacity: Uneven fracture
Streak: White
Synonyms/varieties:
Comments:
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