Mineralpedia Details for Geigerite
Named after Dr. Thomas Geiger of Switzerland who stidies the Falotta manganese ores where Geigerite gets its type locality in the Falotta mine in Switzerland. It occurs in two additional localities in the Gozaisho mine on Honshu Island in Japan and at the Monte Negro mine in Liguria, Italy. Geigerite is found formed by the metamorphism of manganese oxide ores in radiolarite cavities.
Ref. Handbook of Mineralogy, Anthony et al (1995) and MSA at http://www.handbookofmineralogy.org/pdfs/geigerite.pdf
Geigerite from Monte Nero Mine, Rocchetta Vara, La Spezia Province, Italy
Colorless bladed crystals of Geigerite in flat-lying sprays to 3mm and singular micro-blades on chert matrix with traces of Domekyite, Cuprite and Neotocite.