NOTES ON THE MINERALS OF JAPAN. 235 



KAMiYAMA ill Omî, showÎDg druses of minute crystals of a white 

 colour. The crystal-forms agree with those of thomsenolite and 

 ralstonite. 



E. Carbonates, &c. 



49. Calcite. 



Good crystals of calcite are found in the metallic veins of 

 Ant, Kamioka and of other places. We find, for instance, 

 rhombohedral crystals looking like cubes, at the zeolite-locality 

 of Maze in Echigo Province, acute and obtuse rhombo hedra at 

 IsHiGURE in Ise, and scalenohedral crystals (Rs) in the copper 

 mines of Maze, Ani, &c. 



Calcite containing a little manganese is found in massive 

 state in the Innai and Aikawa mines. In the latter place, the 

 mineral sometimes occurs in the form of more or less rhombic 

 plates, covered with minute scalenohedral crystals of the same 

 substîince with rounded edges. The thickness of the plate, 

 together with the drusy crystals on both faces, reaches about 

 0.8 cm. The whole structure resembles scalenohedral crystals, 

 joined together on their lateral edges and arranged in parallel 

 orientation. Ko first described this structure and ascribed it to a 

 simple parallel growth of minute supplementary twins of scal- 

 enohedral crystals with a twinning suture at their middle. 



Some crystals from Kamioka are in the combination IE.2. 

 Kz. CO I{ and enclose a simple rhombohedron E, as the main 

 crystal. (Kô's collection). 



