Mineral - Barrerite
Barrerite
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
Na₂(Si₇Al₂)O₁₈ · 6H₂O
Unit Cell
a=13.64 b=18.20 c=17.84 Z=8
Physical Properties
Hardness
3 - 4
Streak
white
Density
Normal (2-3,5)
Cleavage
Perfect after {010}
Fracture
Tenacity
Brittle
Optical Properties
Color
whitecolorless
Birefringence
0.010
Luster
Vitreous
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
orthorhombic
Point Group
orthorhombic-dipyramidal - 2/m 2/m 2/m
Space Group
Cmcm (63)
Habit
tabular
Formation
Magmatic, in felsic volcanic andesites and rhyolites
Paragenesis
Twinning
Rarity
Rather rare
Synonyms
Barrerite
Composition
Elements
Mass
SiO₂
58.82
Al₂O₃
14.75
Fe₂O₃
0.04
MnO
< 0.01
MgO
0.24
CaO
1.66
SrO
< 0.01
BaO
< 0.01
Na₂O
5.97
K₂O
1.76
H₂O
16.40
Italy (Passaglia & Pongiluppi 1974)
Groups and Members
Zeolite-Supergroup
STI-Zeolite-Group
Name and first discovery: Named after the New Zealand chemist and physicist Richard Maling Barrer (1910-1996), who was the first to produce synthetic zeolites. Barrerite was first described in 1974.
Chemism:
Synonyms:
Varieties:
Abbreviation: Bre
Literature
Passaglia, E., & Pongiluppi, D. (1974). Sodian stellerite from Capo Pula, Sardegna. Lithos, 7(2), 69-73.