Higher levels of the vein also contained quantities of baryte (barium sulphate), although at the time this had no commercial value.
It is composed of zinc sulphide and barium sulphate.
Supplies of barium sulphate, mainly from home sources, are sufficient to meet all requirements.
Pressed barium sulphate was used as a working standard for the calibration of 100% reflectance.
The reference was a barium sulphate standard plate.
Readings were standardized for 100% reflectance with barium sulphate.
Six parts by weight of pure glycerine, four parts by weight of water, two parts of barium sulphate, and one part of sugar.
Moreover, the use of hot concentrated hydrochloric acid causes a loss by dissolving barium sulphate.
