An unusual Ni-Sb-Ag-Au association of ullmannite, allargentum, Au-rich silver and Au-bearing dyscrasite from Oselské pásmo “silver” Lode of Kutná Hora Pb-Zn-Ag ore district (Czech Republic)

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F17%3A00485960" target="_blank" >RIV/67985831:_____/17:00485960 - isvavai.cz</a>

Alternative codes found

RIV/60461373:22810/17:43915015 RIV/00025798:_____/17:00000268

Result on the web

<a href="http://dx.doi.org/10.3190/jgeosci.249" target="_blank" >http://dx.doi.org/10.3190/jgeosci.249</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3190/jgeosci.249" target="_blank" >10.3190/jgeosci.249</a>

Result language

angličtina

Original language name

An unusual Ni-Sb-Ag-Au association of ullmannite, allargentum, Au-rich silver and Au-bearing dyscrasite from Oselské pásmo “silver” Lode of Kutná Hora Pb-Zn-Ag ore district (Czech Republic)

Original language description

A rare and unusual Ni-Sb-Ag-Au association of ullmannite, NiSbS, associated with allargentum, Ag6Sb, Au-rich silver, Au9.7Ag85.0Sb2.9, and Au-bearing dyscrasite was found in medieval mine dump material of the Oselské pásmo ”silver” lode of the historic Kutná Hora Pb-Zn-Ag ore district. Ullmannite is the first and only Ni sulphide found in the base-metal paragenesis of otherwise exclusively Ag-(Cu)-(Pb)-Sb sulphosalts. No other nickel mineral is known from this base-metal ore district. The mineral was identified in two polished sections of one sample as anhedral grains up to 50 µm across enclosed in allargentum. The average chemical composition of ullmannite Ni 26.76-27.17, Sb 57.80-59.17, S 15.14-15.28 wt. % corresponds to the empirical formula Ni0.98Sb1.01As0.01S1.00 on the basis of Ni + Sb + S = 3 apfu, i.e. it is close to the ideal formula o with only trace contents of As. Au-rich silver with 15.52-16.34 wt. % of gold was found in association with freibergite and pyrargyrite as an anhedral inclusions up to c. 5 µm across. The chemical composition corresponds to Au9.7Ag85.0Sb2.9 on the basis of 100 apfu. One more gold-containing phase was determined: Au-bearing dyscrasite with ~0.7 wt. % of Au. The sample also produced an example of Ag-rich “bonanza” with stephanite, acanthite, pyrargyrite and miargyrite. The likely source of nickel and gold were the serpentinized ultrabasic bodies, cut by the “silver” lodes in the South of the ore district. The serpentinites contain 2000 ppm of Ni and low but stable contents of Au. Penetration of hydrothermal fluids could have caused the mobilization of nickel and gold in serpentinites and in earlier ore mineralization (arsenopyrite). This process resulted in the breakdown of earlier silver minerals while allargentum, dyscrasite and stephanite crystallized. The discovery of Ni-Sb-Ag-Au association in Kutná Hora ore district sheds new light on the elemental variability of this hydrothermal vein-type deposit of Variscan age.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

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OECD FORD branch

10511 - Environmental sciences (social aspects to be 5.7)

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Journal of Geosciences

ISSN

1802-6222

e-ISSN

—

Volume of the periodical

62

Issue of the periodical within the volume

4

Country of publishing house

CZ - CZECH REPUBLIC

Number of pages

6

Pages from-to

247-252

UT code for WoS article

000423277800003

EID of the result in the Scopus database

2-s2.0-85040966432