Hauerite

Formula	MnS2
Origin	Grube Jeziorko, Tarnobrzeg (Poland)
Description	perfect single crystal with brownish tarnish colour
Classification (Lapis)	Sulfides
Crystal System	Cubic
Hardness	4,0
Colour	Reddish brown to brownish black; in polished section grayish white with very pale brownish hue, with red internal reflections; deep red in transmitted light
Streak	Brownish red
Luminescence
Lustre	Metallic-adamantine
Transparency (Opacity)	Opaque to subtranslucent
Cleavage	Perfect
Fracture	Uneven to subconchoid
Magnetism	Negative
Geological Setting	A low-temperature mineral commonly associated with solfataric waters
Specific Gravity	3,44 g/cm3