I recently discovered the jewelry by Acme Studios and fell in love! Being an artist, I love how they feature different artists’ designs! These are an M. C. Escher design that plays with positive and negative spaces, imagery and color. The black and white design can be worn anytime and they are a perfect medium size at 3/4” square. These are enamel. Not sure of the base metal, but they did clean up when I polished them with a sterling silver cleaning cloth.