These include 15 minerals containing gold and/or silver and 14 tellurides, among which are the lead telluride altaite
, the mercury telluride coloradoite, and the nickel telluride melonite.
This paper underlines the mineralogical characteristics of these deposits by pyrite presence as the main mineral, either disseminated or as sulphur; the absence of arsenopyrite and the occurrence of a variety of minerals such as gold, silver, lead, bismuth and nickel of the telluride's group: Petzite, Calaverite, Silvanite, Hessite, Bolinskite, Shtiutzite, Melonite, and altaite, as well as the presence of gold of high purity and electrum (Torres et al.
In the South sector, the galena and the sphalerite are diffused, the native gold prevails in form of small inclusions in the pyrite; and inside the group of tellurides, the Altaite and silver tellurides are diffused.
Altaite is uncommon, occurring at the Cresson mine as silvery white massive ore (Saunders, 1988; Geller, 1993).
At Cresson, calaverite crystallization overlaps but has primarily occurred after the crystallization of base-metal sulfide minerals, and in some cases it is replaced by petzite, melonite and altaite (Saunders, 1988).
Then, from Level 2 of the Rex mine, Boulder County, brilliant tin-white altaite
, coloradoite, petzite and hessite are intermixed with duller gray massive galena on gray-white miniature-size rock matrix.
Metallic phases are: pyrite, acanthite, hessite, "electrum," altaite
, silver, galena, pyrargyrite, sphalerite and owyheeite.