Mineral - Albite
Albite
Chemical Properties
Mineral Class
Silicates
Toxicity
none
Formula
Na[AlSi₃O₈]
Unit Cell
a=8.14 b=12.79 c=7.16 α=94° β=117° γ=88° Z=4
Physical Properties
Hardness
6 - 6.5
Streak
white
Density
Normal (2-3,5)
Cleavage
Perfect on (001), very good on (010), imperfect on (110)
Fracture
conchoidal,
uneven
Tenacity
Brittle
Optical Properties
Color
whitegraycolorless
Birefringence
0.010
Luster
Vitreous,
Pearly
Transparency
translucent,
transparent
Pleochroism
Geomineralogical Properties
Crystal System
triclinic
Point Group
triclinic-pinacoidal - 1
Space Group
P 1 (2)
Habit
prismatic, tabular
Formation
In plutonites and their pegmatites, basalts and in hydrothermal alpine veins. Through metasomatism, metamorphism with low temperature/pressure
Paragenesis
Twinning
Polysynthetic twins on (001) or (010), multiple directions of contact twins
Rarity
Very common
Synonyms
Albite, Andesine, Anorthoclase, Oligoclase, Bytownite, Labradorite, Pericline, Cleavelandite, Peristerite, Zygadite
Composition
Elements
Mass
SiO₂
68.71
Al₂O₃
19.63
CaO
0.22
Na₂O
11.72
K₂O
0.03
Switzerland (Dana 1892)
Groups and Members
Feldspar-Group
Plagioclase-Subgroup
Name and first discovery : Named after the Latin word "albus" for "white," due to its most common color. Albite was first scientifically described in 1815 by Johan Gottlieb Gahn and Jöns Jakob Berzelius. The type locality is the Finnbo quartz and pegmatite quarry near Falun, Sweden.
Chemistry : The Na-rich end member of the albite-anorthite series (plagioclase)
Synonyms : Kieselsspar, Olafit, Sodaklas, Tetartin
Varieties : Moonstone, Cleavelandite, Pericline, Peristerite, Zygadite
Abbreviation : From
literature
Dana, J. D., & Dana, E. S. (1892). The system of mineralogy of James Dwight Dana, 1837-1868: descriptive mineralogy . J. Wiley & sons.