New studies on mustard gold from the Dongping Mines, Hebei Province, China: The tellurian, plumbian, manganoan and mixed varieties
Li, J.; Makovicky, E.
published: Sep 26, 2001
ArtNo. ESP154017603002, Price: 29.00 €
New studies of mustard gold from the Dongping Mines, Hebei Province, China, allowed to recognize and characterize a number of chemical varieties of this composite material: Type I: mustard gold with (nearly) unfilled micropores; ferroan Type II with pores filled by goethite (Boeck-Petersen et al. 1999); tellurian-plumbian Type III; tellurian-ferroan type IV; varieties of tellurian Type V; mangano-anplumbian Type VI as well as ferroan-tellurian-plumbian Types VII and VIII. Chemistry and properties of these types have been modelled by contents of various tellurates/tellurites/hydroxides in the submicroscopic pores of the mustard gold aggregate. These compositions also explain the insufficiently defined 'oxidic phases' of Au and Te described by Cai (1993) and Tian (1996). Mustard gold was formed by decomposition of calaverite with selective leaching of tellurium while retaining (Au, Ag) in the original cavity. The resulting microporous aggregate has subsequently been filled by the products of ore weathering.