General Information:
Chemical Formula:
Ca(Fe++,Mg,Mn)(CO3)2
Composition:
(Molecular Weight = 206.39 gm)
Calcium 19.42 % Ca
Magnesium 3.53 % Mg
Manganese 2.66 % Mn
Iron 16.24 % Fe
Carbon 11.64 % C
Oxygen 46.51 % O
Empirical Formula:
CaFe2+0.6Mg0.3Mn2+0.1(CO3)2
Name Origin:
Named after the Australian mineralogist, M. J. Anker (1771-1843).
Physical Properties:
Cleavage:
[1011] Perfect, [1011] Perfect, [1011] Perfect
Color:
brown, brownish yellow, gray, gray brown, or white.
Density:
3 - 3.1, Average = 3.05
Diaphaniety:
Translucent to subtranslucent
Habits:
Crystalline - Coarse - Occurs as well-formed coarse sized crystals., Massive - Uniformly indistinguishable crystals forming large masses., Granular - Generally occurs as anhedral to s ubhedral crystals in matrix.
Hardness:
3.5-4 - Copper Penny-Flourite
Luminescence:
None.
Luster:
Vitreous (Glassy)
Streak:
white
More details...