Picrochromite

The hypothetical Magnesium Chromium end-member of the Spinel series.

Structural context

Magnesiochromite
Crystal System isometricCrystal Class hexoctahedralSpace Group Fd-3m

Chemical context

Stoichiometric formulas

Picrochromite
mindat.org
  • March 13, 2023MgCr2O4
mineralogy.rocks
  • Aug. 30, 2022MgCr3+2O4
Magnesiochromite
mindat.org
  • March 13, 2023MgCr2O4Mg may be partially replaced by divalent Fe, and Cr by Al and trivalent Fe.
IMA
  • March 13, 2023MgCr2O4
mineralogy.rocks
  • Aug. 30, 2022MgCr3+2O4

Physical properties

ColorColor entities, recognized using a custom trained NER model
    • deep red
    Color noteOriginal color note from the source
    Black, deep red
    StreakStreak entities, recognized using a custom trained NER model
      Streak noteOriginal streak note from the source
      Brown
      Lustre
      Greasy
      Metallic
      Sub-Metallic
      Fracture
      Irregular/Uneven
      Hackly
      Sub-Conchoidal
      Transparency
      Opaque
      Tenacity
      brittle
      Hardness
      5.5
      Measured density
      4.1—4.3
      Calculated density
      4.43