72.—Tin Ore.
Occurs in crystals, grains and masses; high lustre; powder gray or brownish; brittle; will strike fire with steel; unaltered by heat or acids; gravity 7,—being nearly as heavy as lead-ore.
Value.—The only ore of tin, containing seventy-nine per cent. No gold-mine ever paid such profits as the tin mines of Cornwall.
Localities.—Jackson, N. H.; Temescal, Cal.; Boonville, Idaho; near Fredericktown, Mo.