Mineral - Brewsterite-(Sr)
Brewsterite-(Sr)
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
(Sr,Ba,Ca)[Al₂Si₆O₁₆] · 5H₂O
Unit Cell
a=6,79 b=17,57 c=7,76 β=95° Z=2
Physical Properties
Hardness
5
Streak
white
Density
Normal (2-3,5)
Cleavage
perfekt nach {010}
Fracture
uneven
Tenacity
Optical Properties
Color
whitebrownyellowcolorless
Birefringence
0,014
Luster
Vitreous
Transparency
transparent
Pleochroism
0,014
Geomineralogical Properties
Crystal System
monoclinic
Point Group
Space Group
Habit
coarse, crusty, prismatic
Formation
hydrothermal in Amygdulen vulkanischer Gesteine und Schiefern
Paragenesis
Twinning
Parallel nach {010}
Rarity
Rather rare
Synonyms
Brewsterite-(Sr), Brewsterite
Composition
Elements
Mass
SiO₂
54,4
Al₂O₃
15,3
Fe₂O₃
0,1
CaO
1,2
SrO
9,0
BaO
6,8
Na₂O
0,2
K₂O
0,1
H₂O
13,2
Schottland
Groups and Members
Zeolith-Gruppe
BRE-Zeolith-Strukturgruppe
Brewsterit-Serie