Cafarsite

This rare mineral, a calcium arsenite with varying amounts of titanium, iron and manganese, was described by Dr Stefan Graeser in 1966. Cafarsite was found in the Lercheltini zone of the Binntal more than 100 years ago, but was named arsenoferrite due to an incorrect analysis of its chemical composition.
Cafarsite occurs in alpine fissures in various types of gneiss, presumably mainly in the upper part of the Monte Leone strata. For a long time, the Binntal-Devero region was the only place in the world where cafarsite was found. In 1986, cafarsite was also found in the Canadian gold district of Hemlo/Ontario, but exclusively in a coarse, fine-grained formation.