input: [0] Colorless to White or Grey, may be tinted other colors [1] 3½ to 4 [3] STRONTIANITE (Aragonite Group) SrCO3 [4] Orthorhombic [5] usually in granular or fibrous aggregates, may be columnar, crystals short prismatic to acicular, often pseudo-hexagonal in cross- section (Ca-rich) [6] 3.76 [7] effervesces mildly in cold acids, or not at all. Distinguished from cerussite by its notably lower specific gravity, lighter feel. Also it is not as common as cerussite. [2] 
output: vitreous to sub-vitreous, silky when fibrous