GEM-STONES 



MINOR GEM-STONES 



Jade and Jadeite 



20-30 ; also Rev. Min. Prod. Ind., 1905, xxxii., pt. i., 108-9. The ydqut, 

 chunri, mehtab. 



Composition. 



Supply. 



Workings. 



Jaipur 



Jewellery. 



Oriental 

 Garnets. 



D.E.P., 

 iv., 535-41. 

 Jade, 

 Jadeite, 

 Jadestone. 



Bnrma. 



Garnets are silicates of alumina, iron, lime, magnesia or similar bases. They 

 may be grouped in six sections as alumina-lime, alumina-magnesia, alumina- 

 iron, alumina-manganese, iron-lime and lime-chrome garnets. 



Sources. The garnet is common in various localities in India, those of 

 Rajputana being the most important. Some stones from Rajputana are said 

 to measure a quarter of an inch to six inches in diameter, and are reputed to be 

 the best in the world. In the Madras Presidency they occur in Vizagapatam, 

 Godavari, Trichinopoly and Tinnevelly, and are fairly abundant in Burma. 

 According to Holland, " The only garnets worked to any considerable extent 

 in India occur in the mica schists of Rajmahal in Jaipur, and near Sarwar in 

 the adjoining State of Kishengarh. Returns are not available to show the con- 

 dition of the industry in Jaipur, but there is still a considerable industry in the 

 Kishengarh State, though the yearly estimates are altogether too variable to 

 permit of a fair average being drawn, varying from about 10,000 to 2,000." 



Cut garnets in the form of necklaces and other small articles of personal 

 adornment constitute an important section of the lapidary craft of India 

 (Watt, Ind. Art at Delhi, 1903, 74-5). The chief centre of the production of 

 these goods is Jaipur. The qualities known are the so-called amethystine or 

 Oriental garnets, which are usually cut in the form of pendants for jewellery, 

 and the more valuable noble or almandine garnets. 



[Cf. Garcia de Orta, 1563, Coll., xliv. ; Milburn, I.e. ii., 288 ; Min. Prod. Ind. 

 Rev. and Agri. Dept., 1892, 3 ; Min. Rev., 1894, 17 ; 1895, 39-40 ; 1896, 39 ; 

 1897, 37-8 ; Introd. Chem. and Phy. Study Ind. Min., 1895, 81 ; Scott, Oaz. 

 Upper Burma and Shan States, 1901, ii., pt. ii., 230 ; Bennet Brough, I.e. 174-5.] 



10. Jade and Jadeite. Ball, Man. Econ. Geol. Ind., 1881, iii., 

 516-8 ; Fritz Noetling, Rept. Econ. Res. of Amber and Jade Mines Area, 

 Upper Burma, in Rec. Geol. Surv. Ind., 1892, xxv., pt. iii. ; Occurrence 

 in Upper Burma, 1893, xxvi., pt. i., 26-30 ; Baner, Jadeite from Tammaw, 

 Upper Burma, 1895, xxviii., pt. iii., 91-5 ; Holland, I.e. 52-4. The yashm, 

 sang-i-yashab, sutashi, etc. Under the name JADE several different minerals 

 are included, not always easily distinguishable. True jade or nephrite is 

 a native silicate of calcium and magnesium, and may be regarded as a 

 crypto-crystalline variety of hornblende. JADEITE, commonly confused 

 with true jade, is a silicate of soda and alumina, is harder and has a higher 

 specific gravity and greater fusibility than jade. Both jade and Jadeite are of 

 economic importance and are comprised under the general term JADESTONE. 



Sources. The chief source of the mineral is in Upper Burma. According 

 to Holland, some of the best material is obtained as pebbles in the gravels of the 

 Uru river, a tributary of the Chindwin, but most is obtained by quarrying near 

 Tammaw, in the Mogaung Sub-Division of the Myitkyina district. The Jadeite 

 here is enclosed in an eruptive rock closely resembling serpentine which pierces 

 strata probably of Upper Miocene age. No jade (nephrite) of the kind which 

 would be regarded as a marketable mineral is known in India, though a mineral 

 having the essential composition and approaching jade in physical characters 

 is known in South Mirzapur. Outside India it may be remarked that in South 

 Turkestan true jade has been worked for many centuries. 



Mining. The method of extraction is very primitive. Before the discovery 

 of the Tammaw mines, the mineral was obtained only in the form of boulders 

 in the Uru valley, mixed with other rocks in the alluvial deposits of the river. 

 " The boulders are obtained either by digging holes along the bank of the stream 

 or by diving to its bottom. The boulders brought to the surface are at once 

 broken, and the jadeite separated from the useless stuff " (Noetling). In the 

 Tammaw mines the method employed is to heat the surface of the rock by large 

 fires, the fall of temperature by night being sufficient to crack the rock. Crow- 

 bars are then inserted in the cracks and the big blocks thus obtained are broken 

 by mallets into lumps of convenient size. 



Manufactures. Jade is highly valued by the Chinese, and also by certain 

 classes in India. The best is of an intense bright-green colour, but red and pale 

 pinkish varieties are also prized. In Burma it is employed chiefly in the manu- 



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