Mineral - Hedenbergite
Hedenbergite
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
CaFe²⁺[Si₂O₆]
Unit Cell
a=9.85 b=9.03 c=5.24 β=105° Z=4
Physical Properties
Hardness
5.5 - 6.5
Streak
white
Density
Heavy (3,5-6)
Cleavage
Distinct after {110}
Fracture
conchoidal,
uneven
Tenacity
Brittle
Optical Properties
Color
blackbrowngreen
Birefringence
0.025
Luster
Vitreous
Transparency
translucent,
transparent,
opaque
Pleochroism
Geomineralogical Properties
Crystal System
monoclinic
Point Group
monoclinic-prismatic - 2/m
Space Group
C2/c (15)
Habit
lamellar, acicular, radial, columnar, prismatic, radial, tabular
Formation
(1) Metasomatic, in calcareous skarns through the reaction of magmatic fluids with carbonate rocks; (2) Metamorphic, through contact or regional metamorphism of iron-rich, silicate carbonate rocks; (3) Magmatic, through primary crystallization from differentiated, iron-rich magmas such as syenites or alkaline granites.
Paragenesis
Twinning
Rarity
Common
Synonyms
Hedenbergite
Composition
Elements
Mass
SiO₂
48.00
Al₂O₃
0.63
Fe₂O₃
3.32
FeO
22.25
MnO
0.81
MgO
2.12
CaO
20.35
Na₂O
0.34
K₂O
0.18
H₂O
1.72
Italy (Dana 1895)
Groups and Members
Pyroxene-Group
Clinopyroxene-Subgroup