64 
AMERICAN GEOLOGY. 
particles, or they may be very large. Hence, when the parti¬ 
cles of composition are regarded, a granite is fine or coarse. 
Granites differ in color. The fine are gray, usually; the coarse 
are white, or. nearly so. Granites of an intermediate texture 
may be either gray or flesh color. The fine and very coarse 
are rarely flesh color. The quartz is sometimes rose red, but 
usually gray, and never crystallized. The mica in the fine 
granite, is nearly black. In the coarse, the mica is greenish, 
and in some cases black or very dark green. Mica is frequently 
wanting. Sometimes its place is supplied by hornblende. This 
last commixture of minerals constitutes the sienite of authors, 
provided the arrangement is granitic; or if the mica is inter¬ 
mixed with hornblende, it is still regarded as a sienite. 
The variability of granite is seen in its coarseness or fine¬ 
ness. The extreme of these kinds will be found in the veins, 
traversing gneiss, or mica slate. The mica and feldspar is in 
large sheets and blocks; the former occupying, very frequently, 
the middle of the vein, and standing with its edges to the cen¬ 
ter. In other varieties where albite is present, this occupies 
the center, and is arranged in imperfect stellated laminae, which 
are usually hemitropic. Such is the case with the veins of 
coarse granite at Chester and Chesterfield, Mass. These veins are 
well defined at their borders, and usually contain some variety 
of tourmalin. It is mostly indicolite at Chester, but at Ches¬ 
terfield, black, blue, green, and red occur. So at Topsham and 
Brunswick, Me., the coarse granites resemble those already 
referred to. Their width varies from one inch to forty or fifty 
feet. The hills of primary rocks, of which*these coarse veins form 
a characteristic feature, are peculiar to the New England states, 
extending on the south to the Long Island sound, and to Maine 
on the north. 
The coarse granitic beds occur at numerous places. Chester, 
Russell, South Hampton lead mine, Granville, northern New 
York, Pennsylvania, New Hampshire and Maine. The feldspar 
is white and bluish white, and predominates in the mass, while 
the mica is poorly represented. Feldspar in moderately large 
