QUARRIES IK WASHINGTON COUNTY. 
173 
Sizes and percentages of minerals in granite from Hardwood Island, as deter 
mined by the Rosiwal method. 
Mineral. 
Reddish orthoclase . . 
Milk-white oligoclase 
Biotite 
Smoky quartz 
Total 
First test. 
Inches. 
10. 12 
8.00 
• 1. 72 
20. 36 
40. 20 
Second 
test. 
Inches. 
12. 4G 
8.24 
1.54 
17.96 
Averages. 
Inches. 
11.29 
8.12 
1.63 
19.16 
Per cent. 
28.85 
22.45 
4.05 
44.65 
40. 20 
40. 20 
100. 00 
Percentage of both feldspars, 51.30. 
This granite takes a fine polish, in which the contrasts between 
the pinkish and white feldspars and the black mica stand out on the 
background of smoky quartz. Some of the pinkish feldspars are 
bordered by the white. The large size (usually one-tenth inch) of 
the biotite scales is against the durability of the polish under long- 
continued outdoor exposure. 
The quarry measures 150 by GO feet, and 15 feet in depth, but its 
bottom is between tide levels. There is no stripping. 
Rock structure : The sheets, from 2 to 10 feet thick, are horizontal, 
but in places curve seaward. Joints striking N. 75° W., and dipping 
65° S. recur only at rare intervals. Others, striking N. 45° W. 
and vertical, recur at intervals of 18 feet and over. The rift is 
vertical with course N. 10° E. Dikes of aplite up to 6 inches thick 
strike N. 25° W. 
The plant consists of 1 derrick. The cutting plant is at Rockport, 
Mass. 
Transportation is effected by lifting the blocks onto the wharf, 
which is 125 feet from the quarry. 
The product is used for buildings and finds a market in Philadel- 
phia, New York, and Baltimore. Specimen buildings : The wain- 
scoting and stairway in main entrance to Suffolk County court- 
house in Boston ; the American Baptist Publication Society building 
in Philadelphia, and 25 columns in the Catholic cathedral in Newark, 
N.J. 
The Marshfleld quarry is in the town of Marshfield, 3 miles north 
of Machias. Operator, Machias Granite Company, Machias, Me. 
The granite (specimen 84, b) is a biotite granite of pinkish-gray 
color and of medium to fine even-grained texture, with feldspars 
from one-tenth to two-fifths inch and sparsely disseminated biotite 
under one-tenth inch in diameter. It consists, in descending order of 
abundance, of pinkish potash feldspar (orthoclase), smoky quartz, 
cream-colored soda-lime feldspar (oligoclase), and a little black mica 
(biotite), together with accessory magnetite, titanite, and zircon and 
secondary kaolin, white micas, and chlorite. The orthoclase is inter- 
