APOPHYLLITE FROM GOBESSHO IN ÔTSU CITY, JAPAN

抄録

Apophyllite occurs in irregular veinlets (about 3mm wide) which consist mostly of micro-crystalline (about 3μ long) of apophyllite itself, and cuts the associated wollastonite and marble, in a contact metamorphosed lenticular limestone of the palaeozoic age at Gobessho in Ôtsu City, Japan. It is associated with wollastonite, ferrosalite, vesuvianite, grossularite and marble. The hardness is 5, the specific gravity 2.42 (22°C), the luster vitreous, the color pale brownish, the refractive index 1.539±0.002, the chemical formula (K_0.77Na_0.13) (F_0.37OH_0.53) (Ca_3.74Mg_0.34)H_0.36(Al_0.36Si_7.60)O₂₀•8H₂O, and the space group D⁶_4h=P4/mmc.