Japanese Twin
Otome Mine, Makioka-cho, Higashiyamanashi-gun, Yamanashi-ken
The two pieces of quartz are combined under certain rule.
As above figure, the angle made by crystal axes of two quartz is always 84°33’.
In Meiji time, when this quartz had introduced widely in Europe, a German petrologist
Goldschmidt named the specimen as Japanese Twin.
