4.—Anthracite.
Occurs massive; compact; high lustre; brittle; breaks with a curved surface; will not scratch marble; burns, but not readily, with a pale blue flame and little smoke; will not form coke by roasting; gravity 1.4 to 1.8.
Value.—Used for fuel and sometimes cut into inkstands, etc.
Localities.—Found in beds between slates and sandstones, and east of the Alleghany range only, as Eastern Pennsylvania; Portsmouth, R. I.; Mansfield, Mass.; North Carolina. No workable beds will be found in New York.
The rocks in anthracite regions are tilted, bent and broken, never level to any great extent. Impressions of leaves are good indications.