Color is steel or silver gray to black in some forms and red to brown in earthy forms. Sometimes tarnished with irredescent colors when in a hydrated form (called Turgite). Luster is metallic or dull in earthy and oolitic forms. Transparency: Crystals are opaque. Crystal System is trigonal; bar 3 2/m Crystal Habits include tabular crystals of varying thickness sometimes twinned, micaceous (specular), botryoidal and massive. also earthy or oolitic. Cleavage is absent however there is a parting on two planes. Fracture is uneven. Hardness is 5 - 6 Specific Gravity is 5.3 (slightly above average for metallic minerals) Streak is blood red to brownish red for earthy forms. 25kg kraft paper bag 500 1000kg big bag.
