Gold Alloy
An imitation resembling the pure metal in color and of about the same specific gravity is made by melting together in a crucible, well covered with charcoal-dust, copper 7, platinum 16, zinc 1. Mannheim gold, another beautiful imitation, is made in the same way from copper 16, zinc 4, tin 1. Gold 75, copper 25, and a little silver is a remarkable jewelry composition.