specimens have trickled out before from the huge silver mine, but these new pieces display very brilliant rosettes, some with attachments of bright red, pinwheel-shaped aggregates of what is probably proustite (Luis's labels call it pyrargyrite, but proustite seems more likely, as the Uchucchacua orebody is arsenic-heavy, and the association here is with As-rich pearceite
, not Sb-rich polybasite).
has been reported from the Las Chispas mine, but every specimen labeled "pearceite
" which has been X-rayed by the author has proven to be poiybasite.
The new Peruvian pearceite
specimens which Luis Burillo, Jaroslav Hyrsl, and one or two Peruvian dealers had are quite exciting, being some of the best specimens of the rare silver sulfosalt ever found.
The specimens were a roll call of silver species: acanthite, pearceite
, pyrargyrite, polybasite and many others.
Smith (1941) reported polybasite with pearceite
, rhodochrosite, rhodonite, and other silver minerals at the Star West mine.
, stephanite, pyrargyrite and miargyrite also occur in abundance in Guanajuato in addition to the acanthite-naumannite series.
In fact, the locality is well known for small silver specimens and for some rare sulfides such as jalpaite, proustite and pearceite (P.
1994) Jalpaite, pearceite ed altri minerali di argento nelle mineralizzazioni metallifere del granofiro di Boarezzo (VA).
The complex assemblage, currently under study at the Joanneum, includes pearceite
, tiny green spherules of chlorargyrite, and tetrahedrite-tennantite.
Acanthite Bornite Cinnabar Famatinite Native gold Pearceite
Polybasite ProustitePyrargyrite Realgar Native silver Stibnite
In the third stage, conversion of lead-beating minerals to jordanite, replacement of copper-bearing minerals by tetrahedrite, and deposition of pearceite
and proustite took place.
Some excellent pearceite
crystals (to 5 cm) have been seen from the Sarbayskoe mine, near Rudnyi city.