Daisuke Hamane, a technical staff at the University of Tokyo, and Katsuyuki Saito, an amateur mineral researcher, have discovered dozens of platinum group minerals from platinum sand produced in Hokkaido.We clarified that alluvial platinum is an aggregate of various minerals.In addition, it was discovered that the platinum dust collected in Tomamae-cho contains a new kind of mineral, "Tomaeko".
In Japan, the production of platinum dust was confirmed for the first time in Hokkaido in the middle of the Meiji period.As a result, understanding of the mineral composition of domestically produced platinum sand did not progress much.
The research team carried out a search in the hope that the platinum placer deposits that had escaped overexploitation during the war still remain in the northwestern part of Hokkaido.As a result, we succeeded in extracting platinum dust from a total of eight locations in a survey spanning 70 km north-south and 30 km east-west.A full-scale investigation was started for the platinum dust.
Detailed investigation using scanning and transmission electron microscopes revealed more than 40 kinds of platinum group minerals from sand platinum.It became clear that the Japanese platinum dust is by no means simple, but rather an aggregate composed of a wide variety of minerals.
In addition, fine particles with a maximum size of about 20 μm were found in platinum sand collected on the coast of Tomamae-cho.It has a hitherto unknown chemical composition of platinum and copper in a ratio of 1:3, raising the possibility of a new species.Therefore, when we conducted a crystal structure analysis, it turned out to be a structure in which platinum was placed at the corners of the cube and copper was placed in the center of each face. They named it Tomamaeite (scientific name: Tomamaeite).
Tomamae mine embodies a new way of existence of platinum in nature.In the future, the research group hopes to elucidate the unique geological environment that created it and discover unknown minerals.
