Antimony occurs in association with stibnite, gudmundite, arsenopyrite, quartz and carbonates.
Berthierite is a relatively widespread mineral at the Pezinok mine, associated mainly with stibnite and gudmundite. The mineral forms irregular nests, veinlets, and aggregates of small (up to 3 mm), columnar to acicular crystals.
Gudmundite occurs commonly as isolated, anhedral, isometric grains to 2 mm and in aggregates to 5 mm, mainly in stibnite, berthierite, quartz and carbonates.
It is associated mainly with carbonates, gudmundite, pyrite and stibnite.
Using an X-ray spectrometer as the main device in the mineralogical study, the effects of pulp properties (in soda or lime environment) and flotation kinetics were evaluated: gudmundite
(FeSbS) is depressed in soda as well as in a lime environment; boulangerite ([Pb.sub.5][Sb.sub.4][S.sub.11]) gives better results in a soda environment; bournonite ([CuPbSbS.sub.3]) floats very well in both environments and is near to chalcopyrite in its properties.
It is nearly always associated with abundant quartz, gudmundite and dolomite, often with stibnite, and occasionally with pyrrhotite or berthierite.
It commonly forms sharp rhombohedral crystals up to 2 mm, associated with quartz, albite, stibnite and gudmundite. Semiquantitative EDS microprobe analysis shows this dolomite to be enriched in iron, and is thus a ferroan dolomite.
It has been observed as tiny, 1-mm cleavages associated with resinous, pale brown sphalerite and minor gudmundite in quartz, as microscopic inclusions in gudmundite, and as a granular gray mass replacing stibnite on one specimen.
Worldwide, gudmundite is a relatively uncommon mineral, but it occurs fairly abundantly at the Lac Nicolet mine as 1-2 mm prismatic crystals generally resembling marcasite.
Like galena, sphalerite is very rare at the Lac Nicolet deposit, having been confirmed in only a very few specimens as tiny brown grains and cleavages up to 3-4 mm in quartz associated with either galena or gudmundite.
Along with gudmundite and native antimony, stibnite was one of the primary ore minerals mined from this deposit.
Among these minerals are arsenopyrite and chalcostibite, both of which occur sparingly as isolated euhedral crystals in some of the massive native antimony; jamesonite, which was noted as an inclusion in a single grain of gudmundite; and rare, scattered grains of pyrite and chalcopyrite.