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Gedrite [abbr. Ged ]

Year of discovery: 1836 (Gèdre, France), 1934 (Japan)

Locality list: 15 localities of gedrite

• Mg₅Al₄Si₆O₂₂(OH)₂
• [][Mg²⁺₂][Mg²⁺₃][Al³⁺₂][(OH)₂|(AlSi₃O₁₁)₂]^16-

• Class: Mg-Fe-Mn amphibole subgroup < w(OH,F,Cl)-dominant amphibole group < Amphibole supergroup
• Class: Ino-Aluminosilicate (Double chain) - Hydroxide

• Mg => Fe: Ferro-gedrite (Series)

• AlAl => MgSi: Anthophyllite (Series)

• Color: Brown, Green
• Streak: Grayish white
• Luster: Vitreous
• Diaphaneity: Transparent-Translucent

• Cleavage: Perfect on {210} (2 planes, 120 degree), Indistinct on {100} and {001} (2 planes)
• Hardness: 5.5-6
• Density: 3.4

• System: Orthorhombic
• Group: mmm, Pnma
• Lattice: a=18.6, b=17.9, c=5.3