Ten years into a successful medical sales career, Tony Martello (Biological Sciences, ’98) found an unusual quarter in his pocket change — one of the last silver quarters minted and released for circulation, from 1964. He began collecting coins, eventually running across a 1974 silver Eisenhower dollar showing a blue halo effect called rainbow toning. The phenomenon requires a rare convergence of chemical and physical conditions to create beautiful rainbow effects, and such coins fetch a premium from collectors. Martello began studying the phenomenon and searching for rainbow toned coins. The search has now become a treasured hobby and a side business, as he collects and sells unusual rainbow toned coins. “A hobby I found outside of science now combines the chemistry and physics principles I learned at Cal Poly,” he says.