Small serpentine-magnesite bodies that occur in precambrian rocks. They has been quarried for magnesite and serpentine.
References:
- Jøsang, Ottar (1966): Geologiske og petrologiske undersøkelser i Modumfeltet. Norges Geologiske Undersøkelse nr 235, 91-97
- Raade, Gunnar (1970): Dypingite, a new hydrous bascic carbonate of magnesium, from Norway. American Mineralogist 55, 1457-1465
- Raade, G. (1982): Die sogenannten "Martite" von Snarum (Norwegen"). Aufschluss 33: 405-407
- Eldjarn, K.(1988): Etter Neumann". NAGS-nytt 15 (1-4),62 (in norwegian, on a find of pyroaurite ?]
- http://www.nags.net/Nags/english/articles_werner/magnesite_modum.htm