Rosin, also called colophony or Greek pitch, is a solid form of resin obtained from pines and some other plants, mostly conifers, produced by heating fresh liquid resin to vaporize the volatile liquid terpene components. It is semi-transparent and varies in color from yellow to black. At room temperature rosin is brittle, but it melts at stove-top temperature. It chiefly consists of various resin acids, especially abietic acid. The term colophony comes from colophonia resina, Latin for "resin from Colophon", an ancient Ionic city. It is an FDA approved food additive.
A cake of rosin, made for use by violinists.
Pharmaceutical rosin
An etching plate covered with powder resin
Various types of rosin for violins, violas and cellos
In polymer chemistry and materials science, a resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. Resins are usually mixtures of organic compounds. This article focuses mainly on naturally occurring resins.
Insect trapped in resin
Cedar of Lebanon cone showing flecks of resin as used in the mummification of Egyptian Pharaohs
Extremely viscous resin extruding from the trunk of a mature Araucaria columnaris.
The material dripping from an almond tree looks confusingly like resin, but actually is a gum or mucilage, and chemically very different.