Luanheite

Formula:  Ag₃Hg

Origin of name:  After locality; Luanhe River, Hebei, China

Crystal system:  Hexagonal

Crystal class:  6/m 2/m 2/m

Twinning: 

Unit cell: a = 6.61, c = 10.98

Colour:  White, gray white, tarnishes black

Diaphaneity: Opaque

Luster:  Metallic

Habit:  Granular to tabular grains to 10 µm forming irregular spherical aggregates 0.1 to 0.6 mm across with uneven surface

Hardness:  2.5

Specific gravity:  12.5

Cleavage:  None

Tenacity: Malleable

Streak:  Black, grayish black

Synonyms/varieties:

Comments:  Often intergrown with mercurian silver and silicates