General Information: Chemical Formula:Ca(Fe++,Mg,Mn)(CO3)2
Composition:(Molecular Weight = 206.39 gm)
Calcium 19.42 %
CaMagnesium 3.53 %
MgManganese 2.66 %
MnIron 16.24 %
FeCarbon 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...