This large 19th c. brooch is pinchbeck--it looks exactly like 18 karat gold without any hint of brassing such as you might see in a plated piece this old. It's really beautiful. no lead, no verdigris, just bright yellow gold and incredible bright paste stones. It measures 1 & 5/8" and is about 5/8" thick as well. It has a small hook from which to hang a fob, charm, pendant, or watch.