[5] A black colloidal precipitate of CuS is formed when hydrogen sulfide, H2S, is bubbled through solutions of Cu(II) salts.

There is also an amorphous high pressure form[9] which on the basis of the Raman spectrum has been described as having a distorted covellite structure.

[10] The crystal structure of covellite has been reported several times,[11][12][13] and whilst these studies are in general agreement on assigning the space group P63/mmc there are small discrepancies in bond lengths and angles between them.

The structure was described as "extraordinary" by Wells[14] and is quite different from copper(II) oxide, but similar to CuSe (klockmannite).

This contradicts a formulation based on the crystal structure and obeying the octet rule that is found in many textbooks (e.g.[6][20]) describing CuS as containing both CuI and CuII i.e. (Cu+)2Cu2+(S2)2−S2−.