Rubies	87
	with molten igneous material which recrystal-lised the calcium carbonate as pure calcite, while the impurities became the ruby and its associated minerals. The precious stones are but occasionally found in the rock itself, but in an adjacent ground, which the miners call " byon," where the gem stones have weathered out; in the neighbouring river alluvium are found ruby particles, called ruby-sand. Prior to 1886 the rubies were mined by the Burmese with the primitive methods that had been in vogue for centuries, but when, in that year, Burma became part of the British Empire, the work was taken up first by an Anglo-Italian and then by an English company, which paid the Indian Government for this concession of mining rights the equivalent of about f 125,000 annually. Siam has long produced corundum rubies, but the gems are usually darker and inferior to the beautiful clear red stones 'from Burma. The principal mines are controlled by an English company. A few rubies have come from the gem-sands of Ceylon; a few have been found in Mysore and Madras, India; and inconsider­able products in Afghanistan and Australia. Rubies have been found in North Carolina and