General Information:
Chemical Formula:
Pb2Cu(Pb,Bi)Bi2S7
Composition:
(Molecular Weight = 1,328.46 gm)
Copper 4.78 % Cu
Bismuth 39.33 % Bi
Lead 38.99 % Pb
Sulfur 16.90 % S
Empirical Formula:
Pb2.5CuBi2.5S7
IMA Status:
Approved IMA 1968
Locality:
Lime Creek stock, Alice Arm, BC, Canada.
Name Origin:
Named for Edward W. Nuffield (1914-), Canadian mineralogist.
Physical Properties:
Cleavage:
[001] Perfect
Color:
gray, steel gray, grayish green, or reddish brown.
Density:
7.01
Diaphaniety:
Opaque
Habits:
Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline)., Acicular - Occurs as needle-like crystals.,
Hardness:
3.5-4 - Copper Penny-Flourite
Luster:
Metallic
Streak:
grayish black
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