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Cummingtonite

Cummingtonite

Grunerite is an end member of the cummingtonite-grunerite series. Structure and composition are anal-ogous to cummingtonite. The name grunerite is by definition restricted to compositions close to end member Fe7Si8O22(OH)2.

Grunerite

Spodumene

Spodumene

Cummingtonite

Margarite

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Grunerite

Grunerite is an end member of the cummingtonite-grunerite series. Structure and composition are anal-ogous to cummingtonite. The name grunerite is by definition restricted to compositions close to end member Fe7Si8O22(OH)2.

  Hand Specimen identification: Habit, color, two prominent cleavages at 56° to each other, and association help identify grunerite, but it cannot be distinguished from other members of the cummingtonite series without chemical or X-ray analysis. Chemical Composition :Fe7Si8O22(OH)2 Hardness : 6 Specific Gravity3.1 to 3.6 Cleavage/Fracture : two perfect prismatic{110}/uneven …

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Cummingtonite

Cummingtonite

  Hand Specimen identification: Prismatic habit, two perfect cleavages intersecting at near 60° when viewed in basal section, habit, color (if light brown), and association identify cumming-tonite. It may be confused with other amphiboles, especially anthophyllite and gedrite. Chemical Composition :(Mg,Fe) 7Si8O22(OH)2 Hardness : 51 2 to 6 Specific Gravity2.9 to …

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Spodumene

LiAlSi2O6 Origin of Name : From the Greek word spodoumenos, meaning “ashes.” Hand Specimen Identification Spodumene is typically found in pegmatites where it may  form very large crystals. Prismatic cleavage,hardness, color, and association help identify it, but it may be difficult to tell from feldspar or scapolite. it often has …

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