The mineral uytenbogaardtite, Ag₃AuS₂, is a soft, greyish white sulfide mineral, occurring in

hydrothermal Hydrothermal circulation in its most general sense is the circulation of hot water (Ancient Greek ὕδωρ, ''water'',Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with th ...

Au-Ag-quartz veins. It occurs as tiny crystals, visible only with a microscope. It has a metallic luster and a hardness on the

Mohs scale The Mohs scale of mineral hardness () is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. The scale was introduced in 1812 by th ...

of 2 (

gypsum Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywal ...

). It forms, together with

petzite The mineral petzite, Ag3 Au Te2, is a soft, steel-gray telluride mineral generally deposited by hydrothermal activity. It forms isometric crystals, and is usually associated with rare tellurium and gold minerals, often with silver, mercury, ...

(Ag₃AuTe₂) and fischesserite (Ag₃AuSe₂) the ''uytenbogaardtite group''. The type locality is Tambang Sawah,

Bengkulu Bengkulu is a province of Indonesia. It is located on the southwest coast of Sumatra. It was formed on 18 November 1968 by separating out the former Bencoolen Residency area from the province of South Sumatra under Law No. 9 of 1967 and was fi ...

district, Sumatra island,

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

. Common impurities in the uytenbogaardtite are

copper Copper is a chemical element with the symbol Cu (from la, cuprum) and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkis ...

selenium Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, ...

, and

tellurium Tellurium is a chemical element with the symbol Te and atomic number 52. It is a brittle, mildly toxic, rare, silver-white metalloid. Tellurium is chemically related to selenium and sulfur, all three of which are chalcogens. It is occasionall ...

. It is named after the Dutch mineralogist Willem Uytenbogaardt (1918–2012), Professor of Geology, Technical University, Delft, The Netherlands, prominent ore microscopist.

References

{{Reflist Silver minerals Gold minerals Gold(I) compounds Sulfide minerals Trigonal minerals Minerals in space group 161 Minerals described in 1978

See also

References