Frohbergite from the Kobetsuzawa Mine, Sapporo, Hokkaido, Japan
M. Nakata, H. Honma, J. I. Chung and K. Sakurai
Department of Astronomy and Earth Science, Tokyo Gakugei University, Koganei-shi, Tokyo 184, Japan
Department of Geology, College of Natural Science, Chonbug University, Chollabuk-do, Korea
Sakurai Museum, Hirakawa-cho, Chiyoda-ku, Tokyo 105, Japan