The two sections were prepared from an Au ore sample consisting of quartz, galena, and minor altaite, hessite
, and petzite, a common gold-bearing mineral.
Silver-bearing minerals in the deposit include hessite
([Ag.sub.2]Te) and acanthite ([Ag.sub.2]S) (Nast and Williams-Jones 1991) and these minerals may be the source of elevated Ag in till overlying the deposit.
crystallizes in cubic symmetry above 149[degrees] C.
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., 2005; Lopez, 1988; Lopez et al., 1998; Bortnikov et al., 1988).
The color photos of specimens are, for the most part, of good quality, as are the specimens themselves (special and super-salivary honors are hereby awarded to the 8-cm hessite
from Botes, Romania on p.
Stage II includes deposition of milky to smoky quartz, pale purple fluorite, fine-grained pyrite, specular hematite, dolomite or ankerite, celestine, barite, roscoelite, sphalerite, galena, tetrahedrite, calaverite, krennerite, sylvanite, petzite, hessite
, and native gold.
The general hue and cry and the expressions of worshipful awe around those gold cases were just what one would expect, and so, instead of running superlatives predictably around the old track, I will simply say that the major gold cases included the following: Gold Mines of Transylvania (with specimens showing visible crystals of petzite, hessite
and alabandite)--Bill Pinch; a gorgeous case with gold coins, assay scales, books, pictures, etc., and superb specimens including the famous "tree root" California gold--Wayne and Dona Leicht; twelve tremendous old golds from the Burrage collection--Harvard; Native Elements of the Gold Group--A.
Among the array was a large Kongsberg silver curling around in a hook shape, a fine and rare nagyagite, a similarly rare hessite
, crystalline gold and a fine bournonite from England.
The nodules contain numerous inclusions of other species including hedleyite, joseite, hessite
, electrum and graphite.
Highlights included wonderful thumbnails of Pribram proustite and polybasite; thumbnails of Peruvia n proustite and pyrargyrite; amazing miniatures of Romanian hessite
and nagyagite; acanthites from everywhere; and, best of all (to my taste anyway) a 4 x 6-cm cluster of loosely joined, brilliant spheres of miargyrite crystals from the Little Anna mine in Colorado.
At this locality in the spring of 1996, sincosite, a rare vanadium phosphate, was found associated with minyulite and hessite
in gold-bearing siltstone of the lower Cambrian Deadwood Formation.