Both the CCW and the CCE zones contain hydrothermal breccias and multiphase stockwork veins with fine grained sulphides (pyrite,
acanthite and sulfosalts), within andesitic volcanics that have been pervasively altered with silica and adularia, the main alteration assemblage.
The main silver-bearing minerals include nature silver (Figure 4(c)), argentite, and
acanthite, and minor freibergite and sternbergite are also reported [13].
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.
precipitation in the periplasmic space and its bioreduction to elemental silver with a variety of crystal typologies, such as hexagons and equilateral triangles, as well as three different types of particles: elemental crystalline silver, monoclinic silver sulfide
acanthite ([Ag.sub.2]S), and a further undetermined structure [64].
The XRD patterns of the samples treated in the AgN[O.sub.3] solution showed peaks at 2[THETA] = 28.96, 31.52, 34.18, 34.4, 36.86, 40.9, 43.5, 44.32, 45.48, 46.24, 47.48, 48.7, and 63.76[THETA] due to the monoclinic silver sulphide
acanthite [Ag.sub.2]S (14-72).
Pyrargyrite stockwork in siderite and quartz-encrusted cavities, together with
acanthite, native silver, barite, kaolinite, and museum-quality specimens of polybasite and stephanite were noted (Jeff Franzen and Ken Watson, pers.
The drill hole, which the company believes to have been drilled approximately 15-20 metres below the existing mine workings, encountered a 5.15 metre wide mineralized zone containing quartz, silicified andesite breccia, native gold and
acanthite (silver sulfide mineral).
Examples of surface composition modifications with respect to that of the bulk composition as a function of the polishing procedures are illustrated for the case of a chalcopyrite (CuFe[S.sub.2]) mineral in a massive form and as inclusion in a natural
acanthite ([Ag.sub.2]S) matrix.
The alphabetized descriptions of mineral species comprise necessarily the catalog's core: 183 pages of densely packed information,
acanthite through zunyite.
Dull black but of excellent dendritic form, the pseudomorphic "trees" range from thumbnail to small-cabinet size, and some have sharp cubes of
acanthite and/or skutterudite reposing on them.