Bort

A black variety of diamond. Diamond material that is unsuitable for gems because of its shape, size, or color and because of flaws or inclusions. It also occurs in finely crystalline aggregates and is usually crushed into finer material. See also ballas, carbonado.

Structural context

Diamond
Crystal System isometricCrystal Class hexoctahedralSpace Group Fd-3m

Chemical context

Stoichiometric formulas

Bort
mindat.org
  • March 13, 2023C
Diamond
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  • March 13, 2023C
IMA
  • March 13, 2023C
mineralogy.rocks
  • Aug. 30, 2022C

Physical properties

ColorColor entities, recognized using a custom trained NER model
    • colourless
    • champagne-tan
    • lilac
    • yellowish
    • cognac-brown
            Color noteOriginal color note from the source
            Black
            Colourless, yellowish to yellow, brown, black, blue, green or red, pink, champagne-tan, cognac-brown, lilac (very rare)
            StreakStreak entities, recognized using a custom trained NER model
            Streak noteOriginal streak note from the source
            None
            Lustre
            Adamantine
            Greasy
            Fracture
            Irregular/Uneven
            Transparency
            Transparent
            Translucent
            Opaque
            Luminescence
            Some stones fluoresce pale blue, green, yellow, and, rarely, red.
            Tenacity
            brittle
            Hardness
            10
            Measured density
            3.5—3.53
            Calculated density
            3.515