VS
Name
—
Ag₄Cu₂Pb₁₈As₁₂S₃₉
Formula
—
Mineral Species
Entry type
—
Sulfosalts
Chemical class
—
Triclinic
Crystal system
—
1.5–2
Mohs hardness
—
5.8–5.85
Specific gravity
—
Brown-black
Streak
—
Metallic. Anisotropism: Weak. R1 –R2: (400) 38.9–40.0, (420) 38.5–39.8, (440) 38.2–39.4, (460) 37.6–39.0
Luster
—
Perfect on {100}; two others across the flat {100} face
Cleavage
—
—
Space group
—
Cylindrite
Structural group
—
Len · Grandfathered
IMA
—
1905
Named in
—
Steel-gray, may tarnish to iridescence
Typical colors
—
Ag · Cu · Pb · As · S
Elements
—