Identification of Natural and Treated Red Feldspar

Abstract

The main objective of this research is to identify natural red feldspar and treated feldspar. The results of twelve red feldspar samples in this study can be concluded the red color occurs from copper. The mechanism of copper diffusion takes place along a dislocation line as pipe diffusion.
The red color layers from rim toward core were not found in untreated feldspar samples. Also, the mottled color (red and green) were not found distinct in treated feldspars and glistering cloud along red zone were found only in natural red feldspar samples. It is difficult to identify the untreated and treated feldspar from only internal feature. The absorption spectra help to know about pleochroism of the red feldspar, which has mottled color (red and green). All treated feldspars in the study were not shown different polarized spectra in 0p and 90p. LA-ICP-MS result of both natural red and treated red feldspars, the copper content along twinning is higher than perpendicular twinning direction. However, their contents are different in each their red color areas, as in the inner area of natural red feldspars have high copper content while the treated red feldspars have this high content in the outer area or rim of the stones.