General Information:
Chemical Formula:
Fe++3(PO4)2·8(H2O)
Composition:
(Molecular Weight = 501.61 gm)
Iron 33.40 % Fe
Phosphorus 12.35 % P
Hydrogen 3.22 % H
Oxygen 51.03 % O
Empirical Formula:
Fe3+3(PO4)2·8(H2O)
Environment:
Common secondary mineral in the gossan of metallic ore deposits, pegmatates, sedimentary authigenic mineralization in association with organic materials.
IMA Status:
IMA Approved
Name Origin:
Named after the English mineralogist, J. G. Vivian.
Physical Properties:
Cleavage:
[010] Perfect
Color:
colorless, green, blue, dark green, or dark bluish green.
Density:
2.6 - 2.7, Average = 2.65
Diaphaniety:
Transparent to translucent to opaque
Habits:
Divergent - Crystals radiate from a center without producing stellar forms., Concretionary - Rounded massive fine-grained materials., Earthy - Dull, clay-like texture with no visible crystalline affinities, (e.g. howlite).
Hardness:
1.5-2 - Talc-Gypsum
Luminescence:
None.
Luster:
Vitreous - Pearly
Streak:
bluish white
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