General Information:
Chemical Formula:
(Mn++,Ca)Mn++++4O8·(H2O)
Composition:
(Molecular Weight = 419.21 gm)
Calcium 0.96 % Ca
Manganese 64.21 % Mn
Hydrogen 0.48 % H
Oxygen 34.35 % O
Empirical Formula:
Mn2+0.9Ca0.1Mn4+4O8·(H2O)
Environment:
Oxidation zone of a braunite-rhodochrosite-Carpopilite deposit.
IMA Status:
Approved IMA 1970
Locality:
Nomura mine, Ehime, Japan.
Name Origin:
Named for Katsutoshi Takane (1899-1945), professor of mineralogy, Tohoku University, Sendai, Japan.
Physical Properties:
Cleavage:
None
Color:
brownish gray, black, or steel gray.
Density:
3.41 - 3.425, Average = 3.41
Diaphaniety:
Opaque
Habits:
Massive - Uniformly indistinguishable crystals forming large masses., Inclusions - Generally found as inclusions in other minerals.,
Hardness:
2.5-3 - Finger Nail-Calcite
Luster:
Sub Metallic
Streak:
brown black
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