Mineral - Titanite
Titanite
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
CaTi(SiO₄)O
Unit Cell
a=7.06 b=8.71 c=6.56 β=114° Z=4
Physical Properties
Hardness
5 - 5.5
Streak
white
Density
Normal (2-3,5)
Cleavage
Distinct after {110}
Fracture
Tenacity
Brittle
Optical Properties
Color
blackbrownyellowgreen
Birefringence
0.160
Luster
Vitreous,
Adamantine,
Resinous
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
monoclinic
Point Group
monoclinic-prismatic - 2/m
Space Group
P2 1 /c (14)
Habit
axe-shaped, wedge-shaped, massive, tabular
Formation
(1) Magmatic, formed by primary crystallization as an accessory mineral from titanium-rich, calc-alkaline melts (particularly syenites, diorites, and granites).
(2) Metamorphic, formed by the transformation of titanium-bearing phases (such as ilmenite or rutile) in calcium-rich rocks under amphibolite to granulite facies conditions.
(3) Hydrothermal, by precipitation in fractures (Alpine type) or as a product of the alteration of titanium-bearing minerals
Paragenesis
Twinning
Contact- and Penetration-twins after {100}
Rarity
Common
Synonyms
Titanite, Sphene
Composition
Elements
Mass
SiO₂
30.61
TiO₂
39.43
Al₂O₃
0.09
Fe₂O₃
1.14
CaO
28.57
Schweiz (Dana 1895)
Groups and Members
Titanite-Group