VS
Name
—
(Cu,Fe,Ag)₆.₃(Tl,K)₂SbS₄
Formula
—
Mineral Species
Entry type
—
Sulfosalts
Chemical class
—
Tetragonal
Crystal system
—
2–2.5
Mohs hardness
—
6.6
Specific gravity
—
Black
Streak
—
Metallic
Luster
—
Perfect on {001}, indistinct on {100} and {010}
Cleavage
—
I4/mmm
Space group
—
Bukovite
Structural group
—
Ccth · Approved
IMA
—
1966
Named in
—
Lead-gray to iron-black, tarnishes iridescent; creamy white to pale gray
Typical colors
—
Cu · Fe · Ag · Tl · K · Sb · S
Elements
—