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a Spree 
5S J. Lawrence Smith on Emery. 
The diaspore of Gumuch-dagh is also found, of a lamellar 
structure, but very rarely; that of Naxos, Nicaria and Samos are 
all lamellar. Yet of all the specimens that I have collected none 
offer so much interest as those composed of diaspore imbedded 
in corundum; here we see the two minerals passing one into the 
other, without being able, in many places, to distinguish the line 
of separation, so imperceptible is the gradation. After what has 
been said in respect to corundum, it is not astonishing to see this 
connection of alumina more or less hydrated with a hydrate of 
alumina of definite composition. : 
After a knowledge of this fact one might seek to explain the : 
existence of water in corundum, by the intimate mixture of dias- 
pore with this mineral ; if this be the case, the crystal of corundum 
from the Carnatic, which gave me three per cent. of water, must 
contain twenty-three per cent. of diaspore, although neither the 
eye nor microscope could detect its presence. 
As'to the properties of diaspore, I have nothing to add to what 
has already been published on the subject, except that the speci- 
mens [examined do not decrepitate to the same extent as that of 
Siberia. Its specific gravity is 3-45 and hardness above 7. The 
following analyses were made, the mineral being attacked with 
the bisulphate of soda. They afford the formula, Al H. 
TES Cer See ane 
| Loealiti's. |Bilica | Alumina. | Lime.) Oxyd of Iron. Wate 
Gumug@h-dagh, -| 067) 82-20 “41 ; x 
Gumuch-dagh,............ 082] 83:12 | trace. 0°66 : 
Le eee ree re 0:26 | 82°04 | 0°35 1:06 14°81 
Zinc Spinel.—I possess a single specimen of this spinel in — 
chloritoid on a piece of emery from Gumuch-dagh ; it is in octa- 
hedral crystals agglomerated, of a dark emerald green color; the 
quantity being small I have been prevented from making an ex- 
act analysis. The quantity of oxyd of zinc appears to be from — 
thirty to forty per cent. a 
Pholerite.—A mineral, resembling pholerite in composition, 
has been found with the emery of Naxos associated with emery-~ 
lite. It is white, lamellar, and somewhat crystalline, sometimes 
gre It is soft to the touch like steatite, infusible before 
the blowpipe, and when heated with nitrate of cobalt becomes 
strongly colored blue. It is scratched with the nail, and has 4 
specifie gravity of 2-564. Its composition is identical with the 
pholerite of Guillemin, also with the mineral forming the gangue 
‘of the diaspore of Schemnitz. For analysis it was decomposed 
with carbonate of soda. It afforded :— 
Es v Pholerite of Gangue of diaspore 
Guillemin. of Schemnitz—Smith. 
Silica, 44-41 42-93 
Alumina, A220 42-07 
Lime 12 trace and mag. 
