LithoCat

MineralPolybasite
Formula[Ag6Sb2S7][Ag9CuS4]  
Crystal FormMonoclinic/Prismatic [2/m]
CleavageImperfect on {001}
ColorBlack with dark ruby red internal reflections
Density6.1 – 6.4 g/cm3
DiaphaneityOpaque
FractureConchoidal
Hardness2.5 - 3.0
LustreMetallic
StreakBlack
Type Loc.Freiberg Mining District, Mittelsachsen, Saxony, Germany
Dana 8 Class3.1.7.2
Strunz Class2.GB.15
Mindatmindat.org
WebMineralWebMineral
ID520