Grey, yellow or brown colouration of transparent glass ceramics - provided by addn. of cpds. of molybdenum, tungsten and vanadium respectively

摘要

Transparent glass ceramics, whose crystalline phase consists largely of beta-quartz, are obtd. having a smoke-grey, bright yellow or amber colouration. When a smoke grey colouration is required the ceramic contains 1-800 ppm. Mo oxide, for bright yellow 20-500 ppm. W oxide, or for chestnut brown 5-400 ppm. V oxide. Opt. two or even three of the oxides of Mo, W and V may be added. New colours in glass ceramics are obtd. which are aesthetically suitable for various applications, e.g., china ware.