北海道空知支庁雨龍郡幌加内村産Deweyliteに就いて

抄録

Deweylite, a hydrous magnesium silicate, occurred from serpentine region in Horokanai-mura, Uryu-gun, Hokkaido, and it was yellowish or brownish colour and showed amorphous mass with small druses. Hardness: 2-3. Brittle and with small cracks. Fructure : Conchoidal. Translucent. Luster : vitreous or greasy. Under the microscope, it shows spherulitic texture or granular aggregates and shows amorphous state or weak birefringence. Indices of refraction are lower than 1.54. Decomposed by hydrochloric acid. Chemical analysis of the purified material follows : SiO₂ 41.62, TiO₂ none, Al₂O₃ 0.06, Fe₂O₃ 0.03, FeO 1.35, MnO trace, MgO 33.89, CaO 0.06, H2O (+) 17.60, H₂O (-) 6.13, total 100.74% (analysed by H. Minato in 1958). Spectroscopic analysis shows that its trace elements are Mn. Ti and Ni, and V, As, Sb, P, Cu, Zn, Cr and Co are not detected. Weight loss curve of the specimen by means of thermogravimetric analysis is given, also. X-ray powder pattern of the specimen agrees with that from Yagiyama, Fukuoka Prefecture and from Delaware, New York.