Chaoite

Formula:  C

Origin of name:  For Edward Ching-Te  Chao (1919- ), American astrogeologist, U.S. Geological Survey

Crystal system:  Hexagonal

Crystal class:  6/m 2/m 2/m

Twinning:

Unit cell: a = 8.948 Å, c = 14.078 Å

Colour:  Black

Diaphaneity:  Opaque

Luster:

Habit:  Thin lamellae alternating with graphite

Hardness:  1 to 2

Specific gravity:  3.43

Cleavage:  None

Tenacity:

Streak:

Synonyms/varieties:

Comments:  Polymorphous with diamond, graphite and lonsdaleite. Formed in shock-metamorphosed graphite gneisses and meteorites