turpentine tree: see terebinth.

turpentine, yellow to brown semifluid oleoresin exuded from the sapwood of pines, firs, and other conifers. It is made up of two principal components, an essential oil and a type of resin that is called rosin. The essential oil (oil of turpentine) can be separated from the rosin by steam distillation. Commercial turpentine, or turps, is this oil of turpentine. When pure, it is a colorless, transparent, oily liquid with a penetrating odor and a characteristic taste. It contains a large proportion of pinene, a compound from which camphor is manufactured. Turpentine is obtained in large amounts from several species of pines of the SE United States; its physical properties, e.g., boiling point, depend on its source. It is used chiefly as a solvent and drying agent in paints and varnishes.

Any resinous exudate or extract from conifers, especially pines; now also commonly a term for its volatile fraction, oil (or spirits) of turpentine. Semifluid mixtures of organic compounds consisting of resins dissolved in a volatile oil, turpentines can be distilled (see distillation) into the volatile oil of turpentine and the nonvolatile rosin. The oil, a mixture of monoterpenes (see isoprenoid), chiefly pinene, is a colourless, odorous, flammable liquid that does not mix with water but is a good solvent for many substances. Oil of turpentine is favoured over petroleum solvents as an oil-paint thinner, varnish solvent, and brush cleaner. Its chief use is now as a raw material for resins, insecticides, oil additives, and synthetic pine oil and camphor and as a solvent.

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