Made by P.S.Co an American jewelry company.  The cameo is beautiful.   Can be worn as a pendant or brooch Gold filled 1/20 10K GF

Plainville Stock Co. was a Massachusetts-based jewelry manufacturing business. The firm was founded in the late 1800s and lasted for over a century. It was known for producing a variety of jewelry styles, including many rings.  Please note the actual cameo appears to have been be made from a composite material.  None the less a beautifully made item.