The principal minerals which are found either banded or disseminated within the 90% quartz matrix include pyargyrite, ancanthite, proustite
, polybasite, miargiarite, galena, sphalerite, pyrite, and arsenopyrite.
The fluorites, pink quartzes, even the delicate greens of some spodumene, the faintly blushing calcites and the rhodochrosites, also sensibly succumb to these exposures, while it is a matter of common annoyance to find that the realgars, cerargyrites, proustites
, cuprites, crocoite, and sulphurs go through changes that slowly alter their substance, texture and appearance.
20, D-53227 Bonn, Germany), there is hope, after all, for major improvement in the proustite
specimens which have been trickling for several years now from the famous Imiter silver mine near Ouarzazate, Morocco.
The locality is the Uchucchacua mine, Oyon Province, Lima Department, already famous for its acanthite, silver, proustite
and "arsenpolybasite" specimens.
, O'Brien mine, Cobalt, Ontario, Canada, no.
At Tamdrost proustite
occurs in calcite veins as dark red crystals not exceeding 4 mm, with lollingite and native silver.
They're all here, in multiple samples ranging in quality from "study grade" to absolutely superb: Freiberg acanthite and stephanite, Schneeberg proustite
and erythrite and roselite and uranium-bearing species, Andreasberg pyrargyrite and dyscrasite and fluorite and pink apophyllite, Siegerland malachite and anglesite and millerite and galena, Schwarzwald fluorite and barite and silver, Obermoschel cinnabar and moschellandsbergite, Ems pyromorphite and cerussite, Johanngeorgenstadt mimetite, Ohrenstock hausmannite, Fichtelgebirge topaz and microcline and herderite, Ehrenfriedersdorf cassiterite and fluorapatite, Ilfeld manganite, Ronneburg whewellite, Hagendorf phosphates .
5 ("Mexico II"); the 7-cm cluster of proustite
crystals from Chanarcillo, Chile; the finest extant specimen of spangolite from Bisbee, Arizona; and others almost as well known.
Many cases at the Main Show tackled South American Minerals, the hands-down best of them being the Smithsonian's case, with 21 amazing pieces including a totally gemmy blue 5-cm euclase crystal from Ouro Preto, Minas Gerais, Brazil; a single, thick, lustrous, still-red proustite
Any of the rarer species from Silvermines such as jordanite, proustite
, tennantite etc.
He also got apophyllite and valencianite from Guanajuato, and had spent a week in Zacatecas (10) buying specimens of proustite
, pyrargyrite, stephanite and native silver.
his case of superlative thumbnails, and one of these thumbnails, his resplendent, transparent, emphatically red proustite
from Chanarcillo, Chile, took the Lidstrom award for the show's single best specimen in competition.