Albite

One of the most common members of the Feldspar group. Low- and high-temperature structural modifications exist ('low albite' and 'high albite'), with ordered and disordered Al-Si distribution, respectively. The Na-rich end member of the Albite-Anorthite Series (= Plagioclase). Usually also included by petrologists in the alkali feldspar group, especially High Albite, but not in Mindat. Often associated with potassium feldspar (triclinic microcline or monoclinic orthoclase), with which it may form epitaxial intergrowths.

History

Activities related to discovery and approval of the group members

Structural context

Albite
Crystal System triclinicCrystal Class pinacoidalSpace Group P-1
a7.5028—8.419 (8.1204)
b12.4933—13.298 (12.8254)
c6.9463—7.354 (7.1255)
alpha90—94.49 (93.342)
beta116.01—117.791 (116.5179)
gamma86.786—90.88 (88.9163)
volume574.453—734.999 (662.9889)

Based on 147 measurements

Chemical context

Stoichiometric formulas

Albite
mindat.org
  • March 13, 2023Na(AlSi3O8)
IMA
  • March 13, 2023Na(AlSi3O8)
mineralogy.rocks
  • Aug. 30, 2022NaAlSi3O8

Elements recorded on EPMA

145
Na
145
O
144
Al
143
Si
85
K
84
Ca
19
Fe
4
Ge
1
B
1
Ga

Physical properties

ColorColor entities, recognized using a custom trained NER model
      • bluish
      • greenish
      • reddish
      • colorless
      Color noteOriginal color note from the source
      White to grey, bluish, greenish, reddish, colorless
      StreakStreak entities, recognized using a custom trained NER model
        Streak noteOriginal streak note from the source
        White
        Lustre
        Vitreous
        Fracture
        Irregular/Uneven
        Conchoidal
        Transparency
        Transparent
        Translucent
        Tenacity
        brittle
        Hardness
        6—6.5
        Measured density
        2.6—2.65
        Calculated density
        2.615