24 MEMOIR ON EMERY. 



monopoly will be done away with in virtue of a commercial 

 treaty existing between Turkey and the other powers. If this 

 takes place, the price of emery will be still further diminished. 

 Of the different varieties of emery employed in the arts 

 that of Naxos is still preferred, and with reason, as it is more 

 uniform in its quality than that coming from Kulah and 

 Gumuch; nevertheless, if the best qualities of that from the 

 island of Nicaria are found in abundance, and that only sent 

 into market, it will prove at least equal if not superior to 

 that of JSfaxos. 



PART SECOND. 



ON THE MINERALS ASSOCIATED WITH EMERY: CORUNDUM, HYDRARGIL- 

 LITE, DIASPORE, ZINC SPINEL, PHOLERITE, EPHESITE (A NEW SPECIES), 

 EMERYLITE (A NEW SPECIES), MUSCOVITE, CHLORITOID (A NEW VARIETY), 

 BLACK TOURMALINE, CHLORITE, MAGNETIC OXIDE OE IRON, OLIGIST IRON, 

 HYDRATED OXIDE OF IRON, IRON PYRITES, RUTILE, ILMENITE, AND TITAN- 

 IFEROUS IRON. 



Now that it has been shown that emery is found in consid- 

 erable abundance in certain parts of the world, occupying 

 almost the position of a rock, it is useful to mention the 

 different accidental minerals, or minerals of elimination, that 

 are found with emery, and what new facts have been observed 

 with relation to them. Corundum may be first mentioned. 



CORUNDUM. 



Although emery is constituted principally of corundum, the 

 examination of this substance in its pure state, or rather in the 

 form of those prismatic crystals which I have sometimes found 

 in contact with emery, has brought to light several new and 

 well-established facts that could not have been satisfactorily 

 ascertained from a mixed mineral like emery 



At G-umuch-dagh it is not difficult to find large pieces of this 

 mineral, pure or mixed with a little diaspore and emerylite; 

 sometimes the crystals are very distinct under the form of six- 

 sided prisms. The small crystals found in the cavities are 

 sometimes terminated by a summit of six faces. The color 

 of the corundum found in the different places alluded to in 



