Andesine

A plagioclase feldspar with an albite : anorthite molar ratio ranging from 50 : 50 to 70 : 30. Originally described from Marmato Mine, Marmato, Cauca, Chocó Department, Colombia. Crystals are rare, to 2 cm; commonly massive, cleavable, or granular. Crystals are commonly twinned after Albite, Pericline, and Carlsbad laws. Also twinned after a law similar to the Manebach law.

Structural context

Andesine
Crystal System triclinic
a8.179
b12.88
c7.112
alpha93.44
beta116.21
gamma90.23
volume670.583

Based on 2 measurements

Chemical context

Stoichiometric formulas

Andesine
mindat.org
  • March 13, 2023(Na,Ca)[Al(Si,Al)Si2O8]
mineralogy.rocks
  • Aug. 30, 2022(Na,Ca)[Al(Si,Al)Si2O8]

Elements recorded on EPMA

2
Al
2
Ca
2
Na
2
O
2
Si

Physical properties

ColorColor entities, recognized using a custom trained NER model
    • gray
        • flesh-red
        Color noteOriginal color note from the source
        White, gray, green, yellow, flesh-red.
        StreakStreak entities, recognized using a custom trained NER model
          Streak noteOriginal streak note from the source
          White
          Lustre
          Sub-Vitreous
          Pearly
          Fracture
          Irregular/Uneven
          Conchoidal
          Transparency
          Transparent
          Translucent
          Tenacity
          brittle
          Hardness
          6—6.5