Description
Uytenbogaardtite is a silver-gold sulfide with the chemical formula Ag3AuS2. Impurities are mainly limited to the elements selenium, tellurium, and copper. The white-gray uytenbogaardtite is opaque, has a metallic luster, and an as-yet-unknown streak color. The crystal system is tetragonal-trapezohedral. The average density is 8.29, which is very high for a mineral. Uytenbogaardtite owes its high density to the silver and gold in its crystal lattice: two elements with high densities. The hardness is approximately 2, which is relatively soft. Due to the small size of the crystals and the relative rarity of uytenbogaardtite, very little information is available about the mineral. Uytenbogaardtite is named after the Dutch mineralogist Willem Uytenbogaardt (1918-2012). During his active life, Uytenbogaardt was a professor at Delft University of Technology and a leading ore researcher. The type locality of uytenbogaardtite is Tambang Sawah in the Indonesian province of Bengkulu. Uytenbogaardtite has also been found in Nevada, Colorado, California, and Arizona in the United States, Bolivia, and Russia. There are also potential occurrences of uytenbogaardtite in Uzbekistan and tetradymite. Uytenbogaardtite is formed in low-temperature hydrothermal veins. Together with petzite (Ag3AuTe2) and fischesseriet (Ag3AuSe2), uytenbogaardtite forms the so-called "uytenbogaardtite group." The mineral often occurs in association with gold and silver alloys, acanthite, chlorargyrite, naumannite, and quartz.
