Tar is a viscous black liquid derived from the destructive distillation of organic matter. Most tar is produced from coal as a byproduct of coke production, but it can also be produced from petroleum, peat or wood. Types of tar General The word "tar" is used to describe several distinct substances. Naturally occurring "tar pits" (for example the La Brea Tar Pits in Los Angeles) actually contain asphalt, not tar, and are more accurately known as asphalt pits. Tar sand deposits contain various mi… (More on Tar)