Smythite

Formula: (Fe,Ni)₉S₁₁

Origin of name: for C. Smyth, Jr., American geologist

Crystal system: hexagonal

Crystal class: -3 2/m

Twinning:

Unit cell: 

Colour: jet black, tinge of brown, basal plane light bronze-yellow

Diaphaneity: opaque

Luster: metallic and splendent on basal surface

Habit: crystals hexagonal platy, 0.0 5 to 1.25 mm

Hardness: 1

Specific gravity: about 4.32

Cleavage: 1; basal

Tenacity: 

Streak: dark gray

Synonyms/varieties:

Comments: Ni not essential in formula