Rosin

Solid form of plant resin

Rosin

Rosin, also known as colophony or Greek pitch (Latin: pix graeca), is a resinous material obtained from pine trees and other plants, mostly conifers. The primary components of rosin are diterpenoids, i.e., C20 carboxylic acids. Rosin consists mainly of resin acids, especially abietic acid.

From Wikipedia, under CC BY-SA. More on occurri.