GEOGNOSY OF PENINSULAR INDIA. 251 



dunor. Fire is then applied, and in twelve hours the pots 

 are sufficiently cool to be removed. The stones are now 

 examined, and some are found to be red, others nearly 

 white ; the difference in their respective tints depending in 

 part on the original quality of the colouring matter, and in 

 part, perhaps, on the difference in the heat to which they 

 have been exposed. The annual value of camelian ex- 

 ported from India formerly amounted to 11,000/. The 

 great emporium Tor these articles is the ancient city of 

 Cambay, where a very considerable trade is carried on by 

 the Borah tribe, whose agents purchase the rough stones 

 from the mountaineers, and convey them to Cambay, where 

 they are wrought into various ornamental articles. Such is 

 the low price of labour and of material at Cambay, that a 

 complete set of female ornaments, necklace, bracelets, cross, 

 brooch, and eardrops, ready for setting agreeably to their 

 colour and quality, costs from eight to twenty-five rupees, 

 the usual price ; or, if very fine, from that sum upwards to 

 fifty rupees for the most beautiful set that can be procured. 

 Beautiful jaspers and agates are found in the camelian dis- 

 trict and other parts of India. In general these sihcious 

 minerals are derived from the overlying trap-rocks, in 

 which they occur in cavities, imbedded masses, and ia 

 reins. 



15. Zeolite. — The great overlying trap district contains 

 the principal species of this elegant family of minerals, 

 which are generally found in drusy cavities. 



16. Ihe felspars and micas of the primitive districts, al- 

 though apparently very interesting, have not hitherto engaged 

 the attention of mineralogists. Of the hornblendes, the 

 common, granular, slaty, actynolitic, and asbestiae, have 

 been met with ; but we do not possess any information ia 

 regard to the calcareous and harytic minerals. 



Saline Minerals. — Common salt, carbonate of soda, and 

 nitrate of potash, as already mentioned, occur in considera- 

 ble quantity in some districts, forming the salt, soda, and 

 nitre soils, — but no beds of these minerals have as yet been 

 met with in Southern India. 



Inflammable Minerals. — Diamond. — This beautiful min- 

 eral, the most precious of all the gems, is found at Cudapa, 

 Banaganpilly, &c., in the river-district of the Pennar ; at 

 Cwndapilly, in the district of the Krishna; near to Bttd" 



