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Todorokite (Photo)

Year of discovery: 1934 (Japan as the first occurence in the World)

Locality list: 89 localities of todorokite

• CaMn₆O₁₂,3H₂O
• (Ca,K,Na,Mg,Ba,Mn)(Mn⁴⁺,Mn³⁺,Mg,Al)₆O₁₂,3H₂O
• [Ca²⁺][Mn⁴⁺₄][Mn³⁺₂][O₁₂]^24-,3H₂O

• Class: Oxide - Hydrate
• Radioactive: Very weak

• Color: Brown, Black, Gray
• Streak: Dark brown
• Luster: Metallic
• Diaphaneity: Opaque

• Habit: Acicular, Plumosity
• Aggregate: Reniform, Stalactitic

• Cleavage: Perfect on {100} and {010} (2 planes)
• Hardness: 1.5
• Density: 3.7

• System: Monoclinic
• Group: 2/m, P2/m
• Lattice: a=9.8, b=2.8, c=9.6, β=90.0

Etymology: Todoroki mine in Hokkaido, Japan, where this mineral was discovered for the first time.