Rosenbergite

Rosenbergite is a mineral with the chemical formula AlF3·3H2O. It is colorless. Its crystals are tetragonal to dipyramidal. It is named after Philip E. Rosenberg, a United States geochemist. It is found in the Celtine Mine in Tuscany, Italy and Mount Erebus, Ross Island, Antarctica. It is not radioactive. Rosenbergite is rated 3-3.5 on the Mohs Scale.