134 CORUNDUM^ ITS OCCURRENCE AND DISTRIBUTION". 
EMERY. 
Until recently the only emery known to occur in the United States 
was that at Chester, Mass., and at Peekskill, N. Y., the principal min- 
ing being done at the latter place. Emery has now been found in 
North Carolina in a promising prospect, and also at one locality in 
Virginia. As is stated on page 2G, emery is a mechanical mixture of 
corundum and magnetite, or sometimes hematite. Because of \t> 
striking resemblance to iron ore, especially where it is a mixture of 
corundum and magnetite and is therefore magnetic, the deposits at 
both Chester and Peekskill were first worked as iron ores, and it was 
not for some time that their real nature and value were understood. 
Since then the deposits at Chester and Peekskill have been worked I 
continuous!}^ and extensively. 
Spinel is sometimes associated with the emery and increases inn 
amount until it is largely in excess of the corundum, and the ore passes 
over into what might well be called a " spinel emery." 
MASSACHUSETTS. 
The only deposit of emery that has been found in this State is 
in the vicinity of Chester, where the emery vein has been traced for 
nearly 5 miles. The vein is first encountered about 2 miles northwest! 
of the village of Chester, in a ledge that projects into Westfield Riven 
from its left bank. The vein can be follow^ed almost continuously ^ 
along the line of the strike — south to a little east of south. Tt extends 
across the east slope of Gobble (North) Mountain, droj^s down intoi 
and crosses the narroAV valley of Walker Brook, and then rising, it 
crosses South Mountain and can be followed for over 2 miles to the 
south. The map (fig. 22) shows the general position of this emery* 
vein, the places that have been opened along it, and the location of the 
different emery mills. The emery occurs in an amphibolite, which 
has been described on page 89. 
The first work was done toward the southern end of the vein, abouii 
half a mile north of where it disappears, at what is known as the 
Wright mine. About twenty years ago rather extensive mining was^ 
carried on here, the work consisting of an open cut nearly 1,400 feett 
long that was worked to a depth of (> feet at its southern end and oil 
jibout 30 feet at its northern, with probably an average dej^th of 2C 
feet for the entire distance. Emery varying in width from 3 to 2C 
feet was encountered throughout nearly the entire length of the cut. 
This mine was reopened in 1890, a shaft 87 feet deep having been 
sunk on the vein near the southern end of the cut and drifts run out 
from it. Margarite is the most conspicuous accessory mineral, and 
specimens that can rarely be exc^elled have been found here. 
