Carlfriesite is a rare tellurium mineral with the formula CaTe4+2Te6+O8, or more simplified: CaTe3O8. It has a Moh's hardness of 3.5 and it occurs in various shades of yellow, ranging from bright yellow to a light buttery color. It was named after Carl Fries Jr. (1910–1965) from the U.S. Geological Survey and the Geological Institute of the National University, Mexico City, Mexico. It was previously thought to have the formula H4Ca(TeO3)3, but this was proven to be incorrect. It has no uses beyond being a collector's item.
Carlfriesite is a rare tellurium mineral with the formula CaTe4+2Te6+O8, or more simplified: CaTe3O8. It has a Moh's hardness of 3.5 and it occurs in various shades of yellow, ranging from bright yellow to a light buttery color. It was named after Carl Fries Jr. (1910–1965) from the U.S. Geological Survey and the Geological Institute of the National University, Mexico City, Mexico. It was previously thought to have the formula H4Ca(TeO3)3, but this was proven to be incorrect. It has no uses beyond being a collector's item.
== Occurrence == Carlfriesite is often found in cavities in hydrothermal gold-tellurium deposits. It is found associated with cerussite, chlorargyrite, argentian gold, cesbronite, calcite, dickite, baryte, bornite, galena, hessite and tlapallite. It was first identified in the Bambollita (La Oriental), Moctezuma, Municipio de Moctezuma, Sonora, Mexico. It is also found in another nearby mine, namely the Moctezuma mine.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).