General Information:
Chemical Formula:
Ca2(Co,Mg)(AsO4)2·2(H2O)
Composition:
(Molecular Weight = 444.30 gm)
Calcium 18.04 % Ca
Magnesium 1.37 % Mg
Cobalt 9.95 % Co
Arsenic 33.73 % As
Hydrogen 0.91 % H
Oxygen 36.01 % O
Empirical Formula:
Ca2Co0.75Mg0.25(AsO4)2·2(H2O)
Locality:
Rappold mines, Schneeberg, Saxony, Germany. Rosas mine at Sulcis, Sardinia.
Name Origin:
Named after Gustave Rose (1798-1873), professor on mineralogy at the University of Berlin, Germany.
Physical Properties:
Cleavage:
[010] Perfect, [???] Good
Color:
dark rose red or pink.
Density:
3.69
Diaphaniety:
Transparent to translucent
Habits:
Mammillary - Larger "breast-like" rounded forms resembling botryoidal (e.g. malachite)., Spherical - Spherical, rounded aggregates., Druse - Crystal growth in a cavity which results i n numerous crystal tipped surfaces.
Hardness:
3.5 - Copper Penny
Luster:
Vitreous (Glassy)
Streak:
light red
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