J. Lawrence Smith on Emery. 65 
| Silica, . : ; ; ‘ , 27:20 
Alumina, . , . é . 18°62 
Protoxyd of iron, i > «ee neo eee 
| Magnesia, ‘ ‘ , ‘ . 1764 
Water, : ‘ ‘ . < 10-64 
It is identical with the chlorite of Mont des sept-Lacs which 
gave M. Marignac, 
Silica, ‘ ; ‘ ‘ ; 27°14 
Alumina, ’ d . . + SES 
Protoxyd of iron, ‘ , : 24:76 
Magnesia, é ‘ ; é + 678 
Water, ’ ; ; ; ‘ 11-50 
von Kobell is, 
oMg ¥1+-3(Mg Ie) * Si+-eH. 
Magnetic Oxyd of Iron.—This is found with the emery of 
every locality. It enters into the composition of the emery it- 
i self and is also found on the surface in regular octahedral erys- 
be tals. We find it frequently massive and of strong polarity. That 
A of Gumuch-dagh contains a trace of titanic acid. es 
_ Oligiste Iron.—tt is associated with all the emerys, and some- 
times enters into their composition. It is also found in detached 
masses, either amorphous or as crystallized specular iron. 
Hydrated Oxyd of Iron.—This oxyd of iron is not unfrequently 
found with emery, covering the surface. It is found wit 
Nites having resulted from the decomposition of this mineral. 
Tron Pyrites.—Pyrites is found principally with the emery 
of Gumuch and Nicaria. At the Jatter locality it is in small crys 
tals in the interior of the mass. At Gumuch it is principally on 
the surface but much less abundant than at Nicaria. 
_ Rutile —This oxyd of titanium is found with the emery of 
Gumuch-dagh and of Kulah, where I obtained some large de- 
tached crystals. I have also a specimen, with it in small erys- 
__ tals on diaspore attached to emery from Gumuch-dagh. 
Ilmenite—It has been found on the gangue of the emery of 
Kulah in minute crystals, of the usual form of this mineral. 
Titaniferous iron.——Titaniferous iron is found with almost all 
the varieties of emery that I have examined, but I have analyzed 
te but that associated with the emery of Nicaria. Care being 
9 
Szconp Serres, Vol. XI, No. 31—Jan., 1861. 
