Mineral - Datolite
Datolite
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
CaB[OH|SiO₄]
Unit Cell
a=4.83 b=7.61 c=9.67 β=90.4° Z=4
Physical Properties
Hardness
5 - 5.5
Streak
white
Density
Normal (2-3,5)
Cleavage
Fracture
uneven
Tenacity
Brittle
Optical Properties
Color
redyellowpinkcolorless
Birefringence
0.044
Luster
Vitreous
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
monoclinic
Point Group
monoclinic-prismatic - 2/m
Space Group
P2 1 /c (14)
Habit
spherical, massive, tabular
Formation
Metamorphism, hydrothermal, Pegmatites
Paragenesis
Twinning
Rarity
Rather rare
Synonyms
Datolite
Composition
Elements
Mass
SiO₂
38.00
B₂O₃
19.38
Al₂O₃
0.65
Fe₂O₃
0.28
MnO
0.39
MgO
0.09
CaO
35.39
H₂O
5.97
Canada (Dana 1895)
Groups and Members
Gadolinite-Supergroup
Gadolinite-Group
Datolite-Subgroup