Formula mass 183.54
Color Brass yellow, may have iridescent purplish tarnish.
Crystal habit Predominantly the disphenoid and resembles a tetrahedron, commonly massive, and sometimes botryoidal.
Crystal system Tetragonal Scalenohedral 42m
Twinning Penetration twins
Cleavage Indistinct on {011}
Fracture Irregular to uneven
Tenacity Brittle
Mohs scale hardness 3.5
Luster Metallic
Streak Greenish black
Diaphaneity Opaque
Specific gravity 4.1 – 4.3
Solubility Soluble in HNO3
Other characteristics magnetic on heating