Mineral - Lorenzenite
Lorenzenite
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
Na₂Ti₂(Si₂O₆)O₃
Unit Cell
a=8.71 b=5.23 c=14.49 Z=4
Physical Properties
Hardness
6
Streak
white
Density
Normal (2-3,5)
Cleavage
Distinct after {010}
Fracture
uneven
Tenacity
Brittle
Optical Properties
Color
brown
Birefringence
0.120
Luster
Vitreous,
Silky
Transparency
translucent,
opaque
Pleochroism
Geomineralogical Properties
Crystal System
orthorhombic
Point Group
orthorhombic-dipyramidal - 2/m 2/m 2/m
Space Group
Pbcn (60)
Habit
prismatic, tabular
Formation
(1) Primarily through magmatic crystallization in alkaline syenites (especially nepheline syenites) and their pegmatites.
(2) Hydrothermally, as a late magmatic formation in cavities or fissures of alkaline rock complexes involving sodium- and titanium-rich fluid phases.
Paragenesis
Twinning
Rarity
Rarely
Synonyms
Lorenzenite
Composition
Elements
Mass
SiO₂
35.40
TiO₂
43.16
ZrO₂
0.07
Y₂O₃
0.02
La₂O₃
0.01
Ce₂O₃
0.04
Nb₂O₅
3.89
FeO
0.34
CaO
0.19
SrO
0.01
Na₂O
16.23
F
0.38
H₂O
0.59
O=F₂
0.16
Greenland (Dana 1895)