Kalgoorlieite (IMA2015-119) is a mineral from Kalgoorlie, Western Australia. Kalgoorlieite is a rare naturally occurring telluride mineral with the chemical formula As₂Te₃ (arsenic telluride). It was discovered in 2015 in microscopic grains from historical ore samples taken at the Kalgoorlie Super Pit in Western Australia and was approved as a new mineral in 2016 by the International Mineralogical Association.
Named after the historic mining town of Kalgoorlie, this mineral is notable for its simple composition—unusual for recently discovered minerals—and is closely related to gold-silver telluride ores, though it contains only trace amounts of precious metals. Its discovery helps geologists better understand the formation conditions of the Golden Mile gold deposit. Due to its rarity, kalgoorlieite has no significant commercial value, though its synthetic analogue is used in thermoelectric applications.
Properties
- Mineral Class: Telluride mineral (oxygen-free arsenic–tellurium mineral).
- Crystal System: Monoclinic, prismatic (space group C2/m).
- Appearance: Microscopic, silvery-colored grains (typically only visible under magnification).
- Trace Elements: Contains only minimal amounts of gold and silver, despite being associated with gold ore.
Significance
Because it has a very simple chemical composition yet forms under specific geological conditions, kalgoorlieite can help geologists constrain the formation history and evolution of the Golden Mile deposit.
Practical & Commercial Relevance
In nature, it is so rare that it’s unlikely to be of commercial value. However, the same chemical compound form (As₂Te₃) has been synthesized for thermoelectric applications — materials that convert heat to electricity or vice versa — though the natural form remains of research interest.
Kalgoorlieite is the fourth oxygen-free arsenic-tellurium mineral after benleonardite, debattistiite, and törnroosite.
It was discovered in 2015 by Curtin University academic Dr. Kirsten Rempel while she was checking samples in the Kalgoorlie School of Mines Museum, and declared a new mineral in 2016, after verification and classification.
Occurrences
Kalgoorlieite is a microscopic, naturally occurring telluride mineral from Kalgoorlie, Western Australia, with the formula As₂Te₃. It’s notable for its rarity, simple chemical composition, and potential to inform geological models of one of the world’s most important gold deposits. Its discovery highlights the value of detailed re-examination of historic ore collections with modern analytical tools.
