Wurzite

Formula	(Zn, Fe)S
Origin	Pomorzany Mine, Okusz (Poland)
Description	Calcite crystals on galenite with brown wurtzite.
Classification (Lapis)	Sulfides
Crystal System	Hexagonal
Hardness	3,5 – 4,0
Colour	Deep reddish brown to dark brown to brown-black
Streak	Brown
Luminescence	none observed
Lustre	Resinous, brilliant submetallic on crystal faces
Transparency (Opacity)	Translucent
Cleavage	Easy
Fracture	splintery
Magnetism
Geological Setting	Of hydrothermal origin in veins with other sulfides
Specific Gravity	4,1 g/cm3