1833.) Second Report on the Geology of Hyderabad. 403 
modes of smelting are well known to be very rude, and have been fre- 
quently described*. On calculation I found that the price of their iron 
in its best state was double that of the best Englishiron at home. The 
ore from which the steel is produced, which goes by the name of the 
“« Hyderabad steel,” is the same with that described by Dr. Hyne in 
his travels in India, p. 191. I have not yet seen the process of making 
it, but from a specimen which I found much inferior to the English 
steel in hardness, I should suppose it not to be the same as the Indian 
wootz so much valued at homet. 
Diamond Mines. 
On the banks of the Kistna and within reach of its inundations are 
the celebrated diamond mines of Golconda. It is probable they have 
been so named from their being the property of the sovereign of Gol- 
conda, which kingdom received its name from the celebrated hill fort 
and city called old Golconda, near the modern city of Hyderabad. 
They are situated in a plain on the left bank of the Kistna, formed 
by its alluvium, and bounded on the east by a chain of mountains run- 
ning nearly north and south, on the west by the river, on the north by 
the granite of Sher-Mahomed-pet, and on the south by that of Bezwara. 
In this plain a few peaks of granite of 15 or 20 feet in height are seen 
rising above the surface of the black alluvium, but none are found nearer 
the mines than one mile anda half. The mine situated nearest the 
hills is two miles distant from them. These hills consist of a mixture of 
quartz, felspar, hornblende, and mica, the latter in very small quantity ; 
the hills near them at Condapili are of sienite approaching to green- 
stone, the hornblende being in the greatest proportion. 
_ From the circumstance of these sienitic hills being surrounded by 
granite on all sides, I venture to suppose that they are merely a repeti- 
tion of the phenomenon of the trap veins on a much larger scale, in 
this case forming mountains differing in their constituent parts, but not 
more than I have observed in other instances. The taluses of these 
mountains extend to a very short distance from their bases, and as I 
was not able to find in the rubbish of the diamond mines any substrata 
resembling them, WrERNeER’s supposition that these rocks, which he calls 
trap from the examination of specimens, were the matrix of the dia- 
mond, will prove unfounded. This receives a further confirmation from 
the fact, that one of the mines near Pulichinta is situated on or near 
limestone, and the mine of Malavili 20 miles south-east of Parteal lies 
on granite and is surrounded by that rock. 
* See Journ. As, Soc. ‘vol. i. p. 150. t+ See ditto, p. 245. 
2F 2 
