Mineral - Clinozoisite
Clinozoisite
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
Ca₂(Al,Fe)Al₂[O|OH|SiO₄|Si₂O₇][
Unit Cell
a=8.88 b=5.58 c=10.15 β=116° Z=2
Physical Properties
Hardness
6.5 - 7
Streak
white
Density
Normal (2-3,5)
Cleavage
Perfect after {001}
Fracture
uneven
Tenacity
Brittle
Optical Properties
Color
brownyellowgreencolorless
Birefringence
0.011
Luster
Vitreous
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
monoclinic
Point Group
monoclinic-prismatic - 2/m
Space Group
P2 1 /m (11)
Habit
fibrous, prismatic
Formation
(1) Metamorphic, through regional or contact metamorphism of calcium-rich rocks (e.g., marl or basic magmatic rocks) under low to medium P-T conditions (green schist to amphibolite facies).
(2) Hydrothermal, as a transformation product of plagioclases (saussuritization) or in fissures and veins through alteration of calcium-bearing silicates.
Paragenesis
Twinning
Rarity
Rather rare
Synonyms
Clinozoisite
Composition
Elements
Mass
SiO₂
40.36
TiO₂
0.09
Al₂O₃
30.67
Fe₂O₃
0.61
FeO
1.77
MgO
0.74
CaO
22.62
H₂O
3.50
Finnland (Dana 1895)
Groups and Members
Epidote-Supergroup
Epidot-Group