Geologically, the mountains are composed of sandstones and nummulitic limestones lying on clay-slates and inclosing immense beds of gypsum and rock-salt. But these stratified rocks are broken through and metamorphosed by rocks of igneous origin, such as greenstones and porphyries. The turquoise-bearing veins occur in the metamorphic strata, and the mines proper consist of shafts and galleries in the solid rock. There are also ‘diggings’ in the detritus of disintegrated rock washed down towards the plain, and it is here that some of the best turquoises are found. A number of the mines are ancient and very extensive; and although most of them are now more or less in a state of neglect, Mr Schindler states that the presence of many old shafts—now filled up—for light and ventilation proves that they have at one time been skilfully worked, and were probably then under government control. But they appear to have been, for nearly two centuries, farmed by the villagers, who only think of a quick return for their money, and therefore cut away the rock wherever they see turquoises, without leaving proper supports to prevent the falling in of the mine. Several labourers have at different times been buried in the galleries through the rubbish being badly propped up. The perpendicular depth of one mine is one hundred and sixty feet, and others are nearly as deep. The miners work with picks and crowbars in much the same way as that in which vein-mining is carried on elsewhere; and it is a curious illustration of how slowly long-established processes are altered in the East, that gunpowder should have been used in these mines only within the last thirty years. But it is not strange, as can be seen by some examples of rock-blasting at home, to learn that the results obtained by gunpowder are, in one view, less satisfactory than those got by the pick. The powder does more work, but it is also more destructive, as it breaks the turquoises into small pieces. Here we may say a few words about how it fares with the people who are occupied with the mining, cutting, and selling of the turquoises. About two hundred men work in the mines or at the diggings, and some thirty more—elders of the village—buy the turquoises and sell them to merchants and jewellers. A certain additional number of hands cut and polish the stones; but this work is done elsewhere, as well as in the district where they are found. The population of the villages in the neighbourhood of the mines is about twelve hundred, and the inhabitants, as in most mining districts, are improvident. Nearly all the men, and not a few of the women, are inveterate opium-smokers. Agriculture is neglected. Turquoise-dealing and its gains make the people careless of anything else. As a rule, the money is quickly spent; and men who easily earn a sum fully equal to fifty pounds sterling per annum, have often nothing to eat.