If sulfur is absent the mineral is tellurobismuthite and the formula is then Bi2Te3.

[6] Crystals are rhombohedral, but are rarely distinctly developed; they are twinned together in groups of four; hence the name of the mineral, from the Greek for fourfold.

There is a perfect cleavage parallel to the basal plane and the mineral usually occurs in foliated masses of irregular outline.

[6] The type locality is Zupkov (Zsubko; Schubkau), Stredoslovenský Kraj, Slovak Republic where it was reported in 1831.

[6] It often occurs in high temperature hydrothermal quartz veins associated with native gold and in contact metamorphic deposits.