Mineral - Fluor-Uvite
Fluor-Uvite
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
CaMg₃(Al₅Mg)(Si₆O₁₈)(BO₃)₃(OH)₃F
Unit Cell
a=15.98 c=7.20 Z=3
Physical Properties
Hardness
7.5
Streak
white
Density
Normal (2-3,5)
Cleavage
Fracture
conchoidal
Tenacity
Brittle
Optical Properties
Color
blackbrownorangegreen
Birefringence
0.029
Luster
Vitreous
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
trigonal
Point Group
ditrigonal-pyramidal - 3m
Space Group
R3m (160)
Habit
prismatic, tabular
Formation
Through metasomatism in calcium-rich, contact metamorphic rocks such as marbles or skarns with the addition of magmatic boron- and fluorine-rich hydrothermal solutions
Paragenesis
Twinning
Rarity
Rather rare
Synonyms
Fluor-Uvite, Uvite
Composition
Elements
Mass
SiO₂
35.96
TiO₂
0.62
B₂O₃
11.49
Al₂O₃
26.80
FeO
0.41
MgO
15.20
CaO
5.50
Na₂O
0.13
F
1.49
H₂O
2.74
O=F₂
0.63
Sri Lanka (Kunitz 1929)
Groups and Members
Tourmaline-Group