TerraCollect
Terra
Collect
Minerals
Fossils
Rocks
Localities
Blogs
Log in
Login
Sign in with Google
Loading data...
Minerals - Ettringite | TerraCollect
Mineral - Ettringite
Ettringite
Ca₆Al₂[(OH)₁₂|(SO₄)₃]·26 H₂O
Chemical Properties
Mineral Class
Sulphates
Toxicity
none
Formula
Ca₆Al₂[(OH)₁₂|(SO₄)₃]·26 H₂O
Unit Cell
a=11.23 c=21.44 Z=2
Physical Properties
Hardness
2 - 2.5
Streak
white
Density
Light (<2)
Optical Properties
Color
white
yellow
Birefringence
0.021
Luster
Vitreous,
Silky
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
trigonal
Composition
Elements
Mass
SO₃
18.80
CO₂
0.80
Al₂O₃
7.00
CaO
26.60
H₂O
46.30
Ireland (Palache et al. 1951)
Groups and Members
Ettringite-Group
Karten-Ebenen
Geologische Karte
Satelliten Karte
Cleavage
Perfect after {10
1
0}
Fracture
uneven
Tenacity
Brittle
Point Group
ditrigonal-pyramidal - 3m
Space Group
P31c (159)
Habit
blocky,
prismatic,
prismatic
Formation
hydrothermal, Metamorphose
Paragenesis
Twinning
Rarity
Very rare
Synonyms
Ettringite,
Woodfordite
