Mineral - Perovskite
Perovskite
Chemical Properties
Mineral Class
Oxides and Hydrxides
Toxicity
none
Formula
CaTiO₃
Unit Cell
a=5.45 b=7.65 c=5.39 Z=4
Physical Properties
Hardness
5.5
Streak
white
Density
Heavy (3,5-6)
Cleavage
Imperfect after {001}
Fracture
uneven
Tenacity
Brittle
Optical Properties
Color
black
Birefringence
0.080
Luster
Metallic,
Adamantine
Transparency
translucent,
opaque
Pleochroism
Geomineralogical Properties
Crystal System
orthorhombic
Point Group
orthorhombic-dipyramidal - 2/m 2/m 2/m
Space Group
Pnma (62)
Habit
blocky, dipyramidal, Octahedron, tabular, Cube
Formation
(1) As the primary crystallization product of silica-undersaturated, alkaline magmas (e.g., kimberlite, carbonatite).
(2) Contact metamorphic in impure limestones (skarns) through the reaction of titanates with calcium carbonate.
(3) High-pressure phase transformation of silicates in the upper mantle (precursor to bridgmanite).
Paragenesis
Twinning
Rarity
Rather rare
Synonyms
Perovskite
Composition
Elements
Mass
TiO₂
58.67
CaO
40.69
Italy (Palache et al. 1952)
Groups and Members
Perovskite-Supergroup
Perovskite-Group
Perovskite-Subgroup