Very viscous; dark brown to black; liquid or semisolid; strong characteristic odor; sharp taste; translucent in thin layers; hardens with aging; sp gr, 1.03 to 1.07; boiling point, ranges from 240 to 400 degrees C; soluble in alcohol, ether, chloroform, acetone, glacial acetic acid, fixed and volatile oils, and sodium hydroxide; and insoluble in water. Chief constituents are complex phenols; also present are turpentine, rosin, toluene, xylene, and other hydrocarbons. Used in flotation.