Cairngorm Stone

Cairngorm Stone, or simply CAIRNGORM, a name often given by jewellers, and particularly in Scotland, to brown or yellow quartz or rock-crystal, because found among the Cairngorm Mountains, in south-west Aberdeenshire. The same mineral is found in many other localities, as at Olivet near Orleans, in Bohemia, Brazil, Siberia, &c. In Cairngorm and the neighbouring district of Mar, it occurs both in the granite rock and in the alluvial soil. It differs from common colourless quartz or rock-crystal only in the presence of a very little oxide of iron or manganese, to which it owes its colour. It is much used as an ornamental stone. The yellow variety is not unfrequently called topaz, although quite different from the true topaz, which it resembles chiefly in colour, having neither its hardness nor its brilliancy. The topaz is, however, sometimes found along with it in the granite and gneiss districts of Mar and Cairngorm. The brown variety is sometimes called Smoky Quartz, and when of a good and uniform colour is by some preferred to the yellow.