THE NONMETALLIC MINERALS. 311 



as amounting to only 2 seers; but Colonel Yule, in his book of Marco 

 Polo, states that the produce was 30 to 60 poods (36 Ibs. each) annually, 

 the best qualities selling at prices ranging from 12 to 24 a pood. 

 Mr. Powell's figures perhaps only refer to the exports to India. For- 

 merly the produce from these mines, which must have been consider- 

 able, was exported principally to Bokhara and China, whence a portion 

 found its way to Europe. 



Marco Polo says that the azure found here was the finest in the 

 world, and that it occurred in a vein like silver. The Yamgan tract, 

 in which the mines were situated, contained many other mines, and 

 doubtless Tavernier referred to it when he spoke of the territory of a 

 Raja beyond Kashmir and toward Thibet, where there were three 

 mountains close to one another, one of which produced gold, another 

 granats (garnets, or rather balas rubies), and the third lapis lazuli. 



A small quantity of lajward is said to be imported into the Punjab 

 from Kashgar, and a mine is reported to exist near the source of the 

 Koultouk, a river which falls into Lake Baikal. 



Uses. Ultramarine for coloring purposes has in modern times lost 

 much of its value, owing to the discovery by M. Guimet in 1828 of an 

 artificial substitute. Formerly it was much used as a pigment, being 

 preferred by artists in consequence of its possessing greater purity and 

 clearness of tint. According to Ball, 1 the artificial substitute is now 

 commonly sold in the bazars of India under the same name, lajward, 

 for about 4 rupees a seer, while at Kandahar in the year 1841, accord- 

 ing to Captain Hutton, the true lajward, which was used for house 

 painting and book illuminating, was sold, when purified, at from 80 

 to 100 rupees a seer. Mr. Emanuel states that the value of the stone 

 itself, when of good color, varies, according to size, from 10 to 50 

 shillings an ounce. In Europe the refuse in the manufacture is 

 calcined, and affords delicate gray pigments, which are known as 

 ultramarine ash. 



Lajward is prescribed as a medicine internalh r by native physicians; 

 it has been applied externally to ulcers. That it possesses any real 

 therapeutic powers is of course doubtful. 



Although no longer a source of any considerable amount of the 

 ultramarine of commerce, the compact varieties of the mineral, such as 

 that from Persia, are highly esteemed for the manufacture of mosaics, 

 vases, and other small ornaments. 



8. ALLANITE; ORTHITE. 



This is a cerium epidote of the formula HR II R III 3 Si 3 O 13 , in which 

 R 11 may be either calcium or iron (or both) and R m aluminum, iron, 

 cerium, didymium, or lanthanum. The following analyses are selected 



1 Geology of India, III, p. 528. 



