Gilt metal seal and pocket key with intaglio carved stone base c1850

This gilt metal pocket watch key has a round base set with an agate stone which is decorated with an intaglio of a bird with a leaf in its beak, standing on some stone. The key sits on top with two loops to hang from a chain. The key measures 21mm x 13mm wide and is a size 2-3. The key is in 100% mint condition