I love the simplicity of these and the fact that they are reversible for a 2 for 1 kinda deal.
They're an old design brought back. A gal recently came into my shop wearing one she bought years ago, said it was her favorite, and inspired me to start making them again.
A 1" bar of copper sheet, enameled on both sides with contrasting colors. Hung from 14K gold filled chain with a ring clasp.