Dark brown to black, thick, viscous mixture of heavy hydrocarbons that occurs naturally (left after evaporation of lighter hydrocarbons, as in Trinidad's Pitch
Lake) or as a residue of crude oil
refining or destructive distillation
. Its ability
when heated, moisture repellency, and (depending on the type of additive) a range
of softening points (usually between 57°C to 99°C, or about 135°F to 210°F) makes it an ideal material
for road paving, roofing, and water proofing
applications. Also called bitumen, coal tar, pitch, or tar.