Very attractive repousse copper hot plate or trivet, made during the early 1900s. The hot plate is 7-1/2 inches diameter, decorated with an embossed transitional Art Nouveau to Arts and Crafts organic motif in the center, surrounded by stippling and a feathered scrollwork border. The underside is backed with black wool felt to protect your counters and tabletop. Between the copper and the felt is a layer of stiff white heat absorbent material.
I have not cleaned it of course - there is some light green verdigris in the grooves of the decoration. I've had success removing verdigris using a soft toothbrush and Dawn dishwashing liquid (with a very light touch), more stubborn spots may require vinegar instead of Dawn. A functional yet extremely decorative piece of antique kitchenware.