| Abstract: | Induced growth striations in quartz crystals grown from Al-containing material have been investigated after X-raying them. Earlier results (Bernhardt, Alter) showed that the stripes may occur as strong colored ones on a light background or as light stripes on high coloration background. This behaviour depends on the growth region regarded, and the applied X-ray dose. The position of the stripes may become displaced in dependence of the X-ray dose. The present paper developes a model which may describe this effect only using the diffusion law, the smoky quartz centre model according O'Brien and the Al3+/Na+-distribution in the crystal. Our results must be taken into account when interpreting the growth striations. |
