Mother of Pearl, sparkling white shell with a vintage Chickadee illustration. The base of the button is heavy, smooth, durable, flat, high quality, bright white shell, onto which the artwork is attached, followed by an application of topcoat for a bit more gloss and protection. The glow of the natural shell shows through, creating unique, higher end natural beauty, like a tiny artwork painted on to iridescent shell. 1-3/8" diameter, almost 1/8" thick, shank back button. Hand made and in the USA by Susan Clarke.