Polyphase Inclusions in the Quartz from the Taishu Mine, Nagasaki Prefecture

Abstract

Many polyphase inclusions composed of liquid, vapor and solids are found in the quartz crystals from the Taishu mine. There are three different kinds of solids in the polyphase inclusions; they are 1) minute opaque mineral, 2) transparent cubic mineral, optically isotropic, and 3) transparent. irregular-shaped mineral, optically anisotropic.
When the inclusions are heated the transparent cubic mineral dissolves at 100°C and it is inferred to be halite. The transparent irregular-shaped mineral is presumed to be calcite as it shows a high interference color between crossed nicols and considerably high relief in the salt solution. It is presumed that the concentration of NaCl was about 256g/l at the formation of the inclusions and that the polyphase inclusions were formed under the high temperature condition and from the high concentrated salt solution.