132 CORUNDUM^ ITS OCCURRENCE AND DISTRIBUTION. 
itself. Considerable i)i'ospecting has been done in Pennsylvania, anc 
corundum has been mined in one or two places, but these are no^A 
abandoned. 
Corundum has been found more al)undantly near Unionville, ii 
Newlin Township, Chester County. It is found here in a mass oj 
serpentine rock, with an average width of about 800 feet and a lengtl 
of 1 mile. A number of tons of corundum have been obtained fron 
this mine, but during the last ten years little or no work has beei 
carried on. Associated with the corundum are tourmaline and spinel 
NEAV YORK AND NEW JERSEY. 
The only corundum, except the emery variety, that has been founc 
in New York or New Jersey is in association with the crystalline lime 
stone, described on page GO. The occurrences are of no connnercia.' 
importance, but are of considerable scientific interest. 
No corunchnn whatever has been found associaterl as ith any of th(' 
peridotite rocks or their altered facies that have been k)cated in thest^ 
States. 
CONNECTICUT. 
The first corundum discovered in Connecticut Avas only surfac(' 
specimens and nothing of connnercial importance was developedl 
Early in the century, a mass of cyanite was found at Litchfield 
" associated with talc, sulphuret of iron, and corundum — reported t( 
weigh 1,500 pounds." It has also been found sparingly with silli 
nianite in the vicinity of Norwich. In V,)0'2 Prof. B. K. Emerson, o 
Amherst College, described corundum h'om Barkhamsted, Conn, 
where it occurs in association with cyanitic mica-schist and fibrolit( 
gneiss. The corundum forms a bed between '2 and H inches thick, an( 
is of a (hirk-blue to blue-black color, with occasional ])atches that ar< 
decidedly green. There is no connnercial (piantity of coriuidnm a 
this locality. 
MASSACHUSETTS. 
As has been stated on page 53, corundum has been found near Pel 
ham, in this State, occurring in a zone of biotite, Avhich has resultei 
from the contact metamorphism of a peridotite on gneiss. Incidental 
to the mining of asbestos at this locality several tons of corundum ori 
were taken out and shipped. The deposit has not developed inti 
one of any economic importance. The emery deposits of the Stat 
are, hoAvever, among the most important corundum deposits in th^ 
United States, and these are described on pages 134-137. 
