CAIRNGORM, a yellow or brown variety of quartz, named from Cairngorm or Cairngorum, one of the peaks of the Grampian mountains in Banffshire, Scotland. According to E. H. Cunning ham-Craig, the mineral occurs in crystals lining cavities in highly inclined veins of a fine-grained granite running through the coarser granite of the main mass. Shallow pits were formerly dug in the kaolinized granite for sake of the cairngorm, and the mineral was also found as pebbles in the bed of the river Avon. Cairngorm is a favourite ornamental stone in Scotland and is used in brooches worn with Highland costume.