General Information:
Chemical Formula:
K4(Mn++,Mg,Fe+++,Zn)48(Si,Al)72(O,OH)216·16(H2O)
Environment:
Metamorphosed, weathered zinc deposit. The manganexe analog of stipnomelane.
IMA Status:
Approved IMA
Locality:
Franklin mine, Sussex County, New Jersey.
Name Origin:
Named after its locality and from the Greek philos = 'friend.' The 'friends of Franklin' are those scientific investigators who helped study the unique mineralogy and geology of th is deposit.
Physical Properties:
Cleavage:
[001] Perfect
Color:
dark brown or black.
Density:
2.6 - 2.8, Average = 2.7
Diaphaniety:
Subtranslucent to opaque
Habits:
Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite), Platy - Sheet forms (e.g. micas).,
Hardness:
4 - Fluorite
Luminescence:
Non-fluorescent.
Luster:
Vitreous - Resinous
Streak:
light brown
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