This is a really unusual piece of history! It is multiple layers of paint build up, lightly tumbled to reveal the various colours. The story my supplier told me was that back in the 1960s in San Francisco, some enterprising hippies set up an impromptu sign shop in a disused railway box car, using spray paint to create signs etc. The overspray built up over time. When they left the box car just sat there until a few years ago when it was opened up and the mess they left behind was discovered. Someone recognized the potential of the paint buildup, and this is the result. It is the same principle as Fordite, the lapidary material from car manufacturing overspray. It's a good story!
This specimen is discreetly attached to a clear plastic support.
1 1/16 inches (2.7 cm) wide, 3/8 inch (0.95 cm) deep and 5/16 inch (0.8 cm) tall.