Electron microscope observations on the crack planes of beryl and quartz

Abstract

Parallel growth of minute crystal with c(0001), m(10_??_0), p(10_??_1) and s(1122) has been found on a mechanical crack of pale green colored subtransparent beryl from Ishikawa, Fukushima Prefecture by a replica method under the Hitachi electron microscope type HU II. Some liquid inclusions are also found in pale blue transparent beryl. Liquid inclusions found in quartz can be classified as (a) inclusion with prism and pyramid, (b) inclusion with etched pits on the above planes, and (c) inclusion with concaves of a bamboo-grass leaf like etched pattern. It is considered that the inclusions have changed to the order (c), (b) and (a) progressively.