Rosin, also called colophony or Greek pitch (Latin: pix græca), 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 rosin temperature 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.