in the mass. : ~ Most frequently there is no other ee of the. 
presence of corundum i in emery but its hardness. The oxyd of 
Iron present. 1s always’ under the form of magnetic oxy h ‘ies or 
less mixed with oligiste ;: sometimes it is titaniferons. There are 
aes minerals associated with the emery, all of which will ake 
destribed hereafter. 
The as aspect of this Eritice differs more than is supposed, for 
by. which to judge others, ~ ‘The localities that I have discovered 
furnish me with specimens showing considerable ditfereuce not 
i “only ¢ as Meatie ie: but also in the structure. 
‘he. os emery is of a dark grey with a mottled surface, 
and ebb “points of a micaceous mineral disseminated in th 
‘Inass. © Tt t frequently contains bluish specks or streaks which are 
easily: recognized as being pure corundum. 
The Gumuch-dazh emery is commonly of a fine grain did 
oR dark. blue’ bérdering on black, not unlike certain varieties of mag-. 
. perce) iron ores. With this variety we frequently find pieces of 
-coruridum of some size. The interior of the mass is tolerably 
‘pes from the micaceous specks found in that of Naxos 
The Kulah emery is usually coarse grained, and much’ darker 
than that of Gumuch-dagh, ‘its external surface resembling some- 
times that of chromate'of iron. 
The Nicaria emery in many instances presents a schistose or 
lamellated structure to a very remarkable degree, so much so that 
certain specimerg might pass for gneiss. ‘T’ he color is dark blue 
and somewhat mottled like that of Naxos. ‘There is also much 
that is quite compact found in the same locality. The jamella- 
ted variety contains.an abundance of a micaceous ara which 
in this instance appears to*have determined its struc 
he Samos emery, as yet found only in small sahonitien, and 
in the form of nodules, is uniformly of a dark blue color, some- 
~ times of a coarse grained and at other times of a fine grained 
a ‘Hot unlike. certain varieties of very compact blue lime- 
ne. 
Fracture.—The fracture of emery is tolerably er. — the 
surface exposed is granular of an adamantine aspect ; it is exceed- 
ingly difficult to break when not traversed by fissures or het of a 
lamellated structure as much of that from Nicaria. When re- 
duced to powder it varies in color from that of a dark grey to 
black. babes color of its powder affords no indication of its com- 
mercial v 
The aly examined under the microscope shows the distinct 
sia of the two minerals, corundum and oxyd of iron, 
94 inseparable as the smallest fragment contains the 
Vol. X, No. 80.—Nov., 1850. 46 
£. Lawrence Smith on Emery. 361 
%* 
ett lately, the emery brought from Naxos has been the criterion — : 
