Anisotropic Color Centers in α Quartz. Part I. Smoky Quartz

Abstract

The color center at 460 mμ produced by x-irradiation of naturally colorless or bleached smoky quartz is anisotropic. The absorption maximum of this color center for the extraordinary ray is 460 mμ and for the ordinary ray is 485 mμ. A second anisotropic peak with maximum in the vicinity of 625 mμ for the extraordinary ray is also present. The relative anisotropy of these color centers in a natural, a Bell synthetic and a Brush synthetic quartz are compared and found to be nearly identical in the case of the synthetic quartzes studied. The absorption coefficients of these color centers x-rayed to saturation are compared with total aluminum content for five specimens.