This is an early Victorian pebble pin. The stones are laid out in a tiled design within a silver frame,quite attractive. I haven't seen one like this for quite some time. It's a nice example of pebble Jewellery. It has been acid tested and is silver. I can find no marks on it. It has a replacement clasp , probably had a C-Clasp but now has a safety clasp. It can also be worn as a pendant. It measures 2 inches by 1 9/16 inches.