Host: Japan Association of Mineralogical Sciences
Gratianite occurs as irregular aggregates up to 1 mm in rhodonite-rhodochrosite-quartz ore from the Hagidaira mine, Gumma Prefecture, Japan. It is in association with cosalite, bismuth and ingodite. Gratianite was examined by Gandolfi camera and electron probe microanalyzer (WDS).The empirical formula of gratianite is (Mn0.794Fe0.187Pb0.025)1.006(Bi1.974Sb0.027)2.001(S3.990Se0.003)3.993. The unit cell parameters are a= 12.7123(10), b= 3.91348(12), c= 14.7749(10) A and beta= 115.310(6)°.