Torbernite

A secondary mineral found in the oxidised zones of some uraniferous copper deposits hence the emerald-green colour of this mineral. Often dehydrated to metatorbernite (note that also transparent crystals can already be metatorbernite). Named in 1793 by Abraham Gottlob Werner in honour of Torbern Olof Bergmann [March 20, 1735 Katharinberg, Sweden and July 8, 1784 Medevi, Sweden], Professor of Chemistry and Physics, University of Uppsala (Sweden). 3 x 2cm