Trimetallic. A numismatic piece of three separate components, each a different metal, bonded to make one blank for striking. The Paris Mint was the first to strike, in 1992, a coin for circulation in a three-metal blank, the 20-franc denomination. Usually a center of one metal surrounded by two separate rings of contrasting metals. Canada followed by conducting experiments in 1995-96 of 14 different bimetallic and trimetallic blanks of round, six-, seven-, eight-, nine- and 11-sided blanks. Canada placed a round bimetallic $2 coin in circulation in 1996.

References:

P3 {1996) Coin World, August 19, 1996, p 1, 71.