Cairngorm, also known as Smoky quartz or Smokey quartz, is a variety of quartz crystal found in the Cairngorm Mountains of Scotland. It usually has a smokey yellow-brown colour, though some specimens are a grey-brown. Like other quartz gems, it is a silicon dioxide crystal, with a small amount of ferric oxide impurity which gives it the characteristic colour. It is used in Scottish jewellery and as a decoration on kilt pins and the handles of sgian dubhs (anglicised: skean dhu). The largest known cairngorm crystal is a 23.6 kg (52 pound) specimen kept at Braemar Castle.
Cairngorm, also known as Smoky quartz or Smokey quartz, is a variety of quartz crystal found in the Cairngorm Mountains of Scotland. It usually has a smokey yellow-brown colour, though some specimens are a grey-brown. Like other quartz gems, it is a silicon dioxide crystal, with a small amount of ferric oxide impurity which gives it the characteristic colour. It is used in Scottish jewellery and as a decoration on kilt pins and the handles of sgian dubhs (anglicised: skean dhu). The largest known cairngorm crystal is a 23.6 kg (52 pound) specimen kept at Braemar Castle.