170 
Records of tie Geological Swrveg of India. 
[voL. xir< 
The lustre may be desci’ibed as dull to the naked eye, but glimmering nnder 
the lens. Fracture imperfect conchoidal. On scratching the ore with a knife 
the streak is seen to vary in colour owing to the mottled character of the sub¬ 
stance. Generally it is greenish and brownish-yellow. In the patches which are 
free from green it is browni.sh-red. The fragments which I selected for analy¬ 
sis yielded a buffish-gray powder. Hardness of the ore about 4'0. Specific 
gravity S'SO . It effervesces with cold dilute acid, yielding a green or blue 
solution and leaving a red powder nndissolved. On heating this powder with 
strong hydrochloric acid, ferric oxide is dissolved, and a w’hite powder remains. 
On comparing the description Dr. Thomson has recorded of the ore analysed 
by him with that just given of the oro I have examined, and recollecting that 
Dr. Heyne has stated that the mysorin occurs in an immense nest at Gannypentah, 
and that the ore examined by me was sent as the ordinary ore of the same 
locality, I do not think there is much room for doubt as to Dr. Thomson’s ore 
and mine being the same. The only disorej>ancy of importance so far is in the 
specific gravity. Dr. Thomson found it to be 2-62, I 3-80. It may be observed 
on this point that it seems remarkable that while malachite has a specific 
o-ravity of 3'7—4-0, the corresponding anhydrous carbonate should have as low 
a specifie gravity as 2-62. The low specific gi-avity can scarcely be ascribed to 
impurity, as Dr. Thomson’s analysis shoM'S this to consist almost entirely of ferric 
oxide. 
In the crucial point however—the presence or absence of water—my analysis 
differs fundamentally from Dr. Thomson’s. The fragments selected for analysis 
showed under the lens the brownish-red and green mottling alluded to above. 
Minute veins of malachite and chrysocoUa were also visible, as well as specks of 
chalcocite, it being found impossible to obtain a sufficiency of the substance free 
from such admixture. Minute quantities of barite and probably calcite were also 
present, although they were not detected by the eye. The result of my analysis 
of the ore (dried at 100° C.) was as follows 
Copper oquiv. to ‘56 of S. . . . . ■ • • 2'22 
Copper calculated as cupric oxide.61'46 
Ferric oxide (with tr. of Al^ O 3 ).6’74 
Lime. 
Baryta.‘^5 
Carbonic acid 1518 
Silicic acid. 
Phosphoric acid tr. 
Sulphuric acid.’29 
Sulphur. 
100-67 
The barium sulphate was included in the residue insoluble in aqua regia,^ 
together with the bulk of the silica, which was entirely soluble in alkali. The 
sulphur was clearly derived from the chalcocite. The ferric oxide was evidently 
> The amount of -ivater was determined hy direct weighmont. 
- Also in the residue insoluble in hydroehloric_acid. 
