Brucite from Sasaguri occurs as foliated or fibrous aggregates, associating with calcite and yellowish serpentine. H=2.5; S.G=2.475; ω=1.562, ε=1.581. Chemical analysis gives: SiO₂ 0.33, Al₂O₃ 0.08, Fe₂O₃ 1.69, MgO 64.81, MnO 1.10, H₂O(-)0.39, H₂O(+)31.38, total 99.78. X-ray powder data and D. T. A. curve are also given. The mineral seems to have been formed under hydrothermal condition.

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The author have investigated the crystallinity of galena by means of x-ray spectrometer. It was found that galena showed structural plasticity on heating and grinding. The main results obtained were as follows:
(1) Recrystallization of galena on gentle heating was clearly observed from diffraction peak profile, and the crystallinity was increased in increasing with heating temperature.
(2) Disordered galena because of soluble minor impurities showed lattice expansion on heating.
(3) Crystallinity was destroyed by grinding and was recovered on heating again, and structural plasticity of galena was observed.

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The Ichifusayama granite situating in the border of Kumamoto and Miyazaki Prefectures intrudes discordantly into the basement sedimentaries (Yuyama formation) which are mainly composed of phyllite and sandstone and accommpanied by schalstein and chert, and can be correlated to a part of the Shimanto Group.
The mass can be divided regionally and petrographically into Fûnokiharu-and Ikenomoto-type, both types include various xenoliths in wide area. The later is richer in xenolith than the former. Ikenomoto-type granite and its xenolith are closely related.

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In this paper is presented a detailed subdivision of socalled gabbro-amphibolite zone of the Hidaka metamorphic belt, the axis of island of Hokkaido.
It is composed of four tectonic units which are arranged in the following order from west to east, as is shown in figure I. 1) green schist zone, 2) epidote amphibolite zone, 3) green hornblende schistose amphibolite zone and 4) saussurite gabbro zone.
Concerning zones 1), 2) and 3), their original rock facies are not clearly determinable.
The zone of saussurite gabbro is composed of three varieties of amphibolite, a) hornblende schist facies, b) coarse grained amphibolite (=metasomatic) facies and c) compact amphibolite facies, all of which are derived from saussurite gabbro.
In such a diverse metamorphic process, the different characters of tectonic forces and combined metasomatic effects have been the chief determinants.

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Barite including a little of strontia has been found in roseki from the mine, and it is not seemed to be associated with sericite from the experiments. The roseki from the mine is mostly composed of kaolinite, dickite and sericite, and is often accompanied with diaspor as accessories.

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