part 1.] Mallet: Gneiss of South Mirzapiir and adjoining country. 
21 
The corundum bed is several yards thick, the surface of the hill being covered with 
blocks, some of which are not less than 2 or 3 tons weight, and the supply is practically inex¬ 
haustible. I was informed by a brother of the Eajali of Singrowli, who lives at Kotah, 
that no corundum had been worked for five or six years, until last year, when 125 bullock 
loads were taken to Mirzapiir. A load is three maunds, the total, therefore, being about 
13£ tons. The mahajuns pay for it at the spot 2& rupees per 14 kucha maunds (= 7 pucka 
maunds of 4£> seers), or at the rate of 18 shillings a ton. 
When two pieces of the corundum are rubbed or knooked together in the dark, a very 
beautiful crimson phosphorescence is emitted. When struck pretty hard yellow sparks are 
also thrown oil', which are quite distinct from the crimson light, the latter being elicited by the 
slightest tap. The same effect is produced more brilliantly by striking the stone with a 
hammer, when the crimson light and yellow sparks flash out at every blow sufficiently hard 
to produce the latter. The sparks resemble those from a flint and steel, while the 
crimson light is trno phosphorescence; this red light is so characteristic as to be of consider¬ 
able nse as a rough field-test for recognizing corundum. Quartz, and such other common 
silicious minerals as I have examined which phosphoresce at all, give a yellow or greenish- 
yellow light. 
In 1868-69 I was informed that corundum was also obtained at Beejpur in Mirzapiir 
on the right bank of the Rehr. On visiting the spot my guide took me down into one of 
the nullas in the alluvium and showed me several lumps lying about, but I could find none 
such in the alluvium itself, or in any bed in the gneiss of the neighbourhood from which the 
above lumps could have been derived. This year in conversation with a very intelligent 
Zemindar of Beej pur, I mentioned the above facts, for which he furnished what seems to 
he a very plausible explanation—namely, that some years ago some bullock-loads of corun¬ 
dum from Pipra (eight or ten miles to the west) had been thrown away at Beejpur 
by some brinjarries on account of more profitable employment for their bullocks or some 
other reason. 
The emerald-green mica which occurs in seams in the joints of the corundum has been 
analysed by Mr. Tween, who found its composition to be as follows:— 
Silica 
... 43-53 
Alumina 
... 43-87 
Oxide of chromium 
*91 
Lime 
1*45 
Potash 
... 7-80 
Water 
... 4-60 
102-16 
The high percentage of alumina and small one of silica is what might be expected in 
such a mineral in association with corundum, and the above composition closely coincides 
with that of the mineral named Buphjdlite by Professor Silliinau, Jr., which occurs at IXniou- 
ville, in Pensylvania, in exactly the same association as our Indian one, namely, with corun¬ 
dum and tourmaline. The chief difference is, that the alkali in the American mineral in¬ 
cludes both potash and soda, while in the Indian one it is wholly potash. In the mica, 
however, found by Dr. Smith with the emery of Asia Minor, which he originally regarded 
as muscovite, -but on further investigation referred to Eupbyllite, the alkali is almost 
wholly potash; the presence of 1 per cent, of oxide of chromium to which the Indian 
Eupbyllite owes its color, distinguishing it from that, of both America and Asia 
Minor. The following are its chief characters:—Structure micaceous; hardness = 3'5—4'0; 
