Among many molybdenite deposits so far found in the district concerned, those occurring around Daitō-machi, Shimane Prefecture are the largest yielding almost all amount of the molybdenite ores produced in Japan.
The molybdenite deposits in this district are roughly dividable into two types: one is represented by the deposits associating wolframite and the other by those without it. The deposits pertaining to the latter are further classifiable into the greisenized and non-greisenized ones.