Margarite

Mica Group. Hintze (Vol. 2, 1897) gives Sterzing (Vipiteno), South Tyrol as the TL of margarite and refers to Mohs (1820). In fact, Mohs described the mineral but did not provide an analysis. Therefore, according to von Zepharovich (1873), Greiner Mt. has to be regarded as the TL, based on the data provided by Senger. 2M1 polytype

History

Activities related to discovery and approval of the group members

Structural context

Margarite
Crystal System monoclinicCrystal Class prismaticSpace Group C2/c
a5.1038—5.114 (5.1075)
b8.8287—8.872 (8.8434)
c19.148—19.164 (19.154)
alpha90
beta95.46—95.51 (95.4875)
gamma90
volume858.893—865.48 (861.1728)

Based on 4 measurements

Chemical context

Stoichiometric formulas

Margarite
mindat.org
  • March 13, 2023CaAl2(Al2Si2O10)(OH)2
IMA
  • March 13, 2023CaAl2Si2Al2O10(OH)2
mineralogy.rocks
  • Aug. 30, 2022CaAl2(Si2Al2)O10(OH)2

Elements recorded on EPMA

4
Al
4
Ca
4
H
4
O
4
Si
2
Mg
2
Na
1
Fe
1
Li

Physical properties

ColorColor entities, recognized using a custom trained NER model
  • grayish
  • pale pink
      • colorless
      Color noteOriginal color note from the source
      Grayish, pale pink, yellow, green. colorless in thin section.
      StreakStreak entities, recognized using a custom trained NER model
        Streak noteOriginal streak note from the source
        White
        Lustre
        Vitreous
        Pearly
        Transparency
        Translucent
        Tenacity
        brittle
        Hardness
        3.5—4.5
        Measured density
        2.99—3.08
        Calculated density
        3.077