VS
Name
—
CuPbAsS₃
Formula
—
Mineral Species
Entry type
—
Sulfosalts
Chemical class
—
Orthorhombic
Crystal system
—
2.5–3
Mohs hardness
—
5.38
Specific gravity
—
Chocolate-brown to purple-black
Streak
—
Metallic. Anisotropism: Strong. R1 –R2: (400) 34.8–36.0, (420) 34.6–35.6, (440) 34.2–35.3, (460) 33.9–35.1
Luster
—
Very poor on {001}, {100}, and {010}
Cleavage
—
Pn2_1m
Space group
—
Bournonite
Structural group
—
Seli · Grandfathered
IMA
—
1901
Named in
—
Dark lead-gray to black; in polished section, rose-white
Typical colors
—
Cu · Pb · As · S
Elements
—