Luzonite

Formula:  Cu₃AsS₄

Origin of name:  After locality; Mncayan, Luzon, Philippines

Crystal system:  Tetragonal

Crystal class:  -42m

Twinning: 

Unit cell: 

Colour:  Deep pinkish brown with grayish tinge

Diaphaneity:  Opaque

Luster:  Dull, metallic

Habit:  Crystals equant, rare, usually rough; massive, fine-grained

Hardness:  ~ 3.5

Specific gravity:  4.38

Cleavage:  2; {101} good, {100} distinct

Tenacity: 

Streak:  Black

Synonyms/varieties:

Comments:  Dimorphous with enargite