Alvanite

General Information:
 Chemical Formula:
(Zn,Ni)Al4(VO3)2(OH)12·2(H2O)
 Empirical Formula:
Zn0.75Ni0.25Al4(VO3)2(OH)12·2(H2O)
 IMA Status:
Approved IMA 1959
Physical Properties:
 Cleavage:
[010] Perfect
 Color:
bluish green, blue black, or black.
 Density:
2.41 - 2.49, Average = 2.45
 Hardness:
3-3.5 - Calcite-Copper Penny
 Luster:
Vitreous (Glassy)
 Streak:
gray
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