Mineral - Ankerite
Ankerite
Chemical Properties
Mineral Class
Carbonates
Toxicity
none
Formula
CaFe[CO₃]₂
Unit Cell
a=4.83 c=16.17 Z=3
Physical Properties
Hardness
3.5 - 4
Streak
white
Density
Normal (2-3,5)
Cleavage
Perfectly after {10 1 1}
Fracture
conchoidal
Tenacity
Brittle
Optical Properties
Color
whitebrownorangeyellow
Birefringence
0.200
Luster
Vitreous,
Pearly
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
trigonal
Point Group
rhombohedral - 3
Space Group
R 3 (148)
Habit
leafy, granular, Rhombohedron, rosette, tabular
Formation
Primarily in hydrothermal deposits
Secondary through replacement/metasomatism of carbonates like calcite
Secondary by substitution of dolomite
Paragenesis
Twinning
Twins with (0001), (10 1 0) and (11 2 0) as twin planes
Rarity
Very common
Synonyms
Ankerite
Composition
Elements
Mass
CO₂
42.30
FeO
17.56
MnO
4.92
MgO
7.73
CaO
27.49
Canada (Palache et al. 1952)
Groups and Members
Dolomite-Group
Name and first discovery : Named after the Austrian mineralogist and curator of the Universalmuseum Joanneum, Styria, Austria, Joseph Anker (1771-1843). First described in 1825.
Chemistry :
Synonyms : brown spar, codazzite
Varieties : Mangano-Ankerite, Nickel-Ankerite
Abbreviation : Ank
literature
Palache, C., Berman, H., & Frondel, C. (1952). Dana's system of mineralogy. Geologiska Föreningen i Stockholm Förhandlingar , 74 (2), 218-219.