Bassanite

May occur as pseudomorphs after gypsum. Very similar to omongwaite; structurally related to chinleite-(Y). Apparently a common precursor phase of anhydrite and gypsum (Van Driessche et al. 2012; Ossorio et al. 2014).

History

Activities related to discovery and approval of the group members

Structural context

Bassanite
Crystal System monoclinicSpace Group C2
a6.82—17.518 (10.7312)
b6.82—13.869 (7.4137)
c6.24—12.7505 (10.7437)
alpha90
beta90—133.655 (91.7741)
gamma90—120 (100.3927)
volume251.353—2118.705 (853.3683)

Based on 26 measurements

Chemical context

Stoichiometric formulas

Bassanite
mindat.org
  • March 13, 2023Ca(SO4)·0.5H2O
IMA
  • March 13, 2023Ca(SO4) · 0.5H2O
mineralogy.rocks
  • Aug. 30, 2022CaSO4·0.5H2O

Elements recorded on EPMA

25
Ca
25
O
25
S
24
H

Physical properties

ColorColor entities, recognized using a custom trained NER model
    Color noteOriginal color note from the source
    White
    StreakStreak entities, recognized using a custom trained NER model
      Streak noteOriginal streak note from the source
      White
      Lustre
      Vitreous
      Dull
      Earthy
      Transparency
      Transparent
      Translucent
      Opaque
      Measured density
      2.69—2.76
      Calculated density
      2.731