Augite and Hypersthene Crystals from the Zao Volcanoes.

概要

論文の詳細を見る
(1) No description has hitherto been known of the augite and hypersthene crystals from Zao volcanoes. (2) Most of the augite crystals collected here have an elongated prismatic habit. It is an unusual form for this mineral which looks like hornblende or hypersthene at a glance. (3) Two types of twinning are found. One of these is the crystal with a (100) as the twinning plane, whereas the other is a penetration, twin in which two individuals cross each other at an angle of nearly 60°, and its twinning plane is supposed to be W (122). (4) As the result of the goniometric experiment, twelve new faces have been found for augite, and one new face for hypersthene. In conclusion, the writers wish to express their cordial thanks to Prof. T. Ito of the Mineralogical Institute, Tokyo University for the courtesies he extended throughout the laboratory work, This investigation is a part of "Geological Investigations on the Zao Volcanoes," and its expenditure was payed from the fund for the Scientific Research of Educationary Ministry.
1951-08-30