... Yellow Synonyms: Colophony; Pine rosin CAS No.: 8050-09-7 Gum rosin is made of natural resin, its general formula is ... is made of natural resin, its general formula is C20H30O2. Gum rosin also called colophony, is a solid form of resin ... . It chiefly consists of different resin acids, especially abietic acid. Gum rosin is an important raw material for the manufacture of ...