This is a necklace consisting of a silver chain and silver and black onyx pendant. Pre-owned in very good condition. The pendant is oval in shape and is an oval black onyx stone in a silver frame with an accent diamond in the center. The chain is 16".  The chain is stamped 925, but not sure if original to the pendant. The pendant has no marks but does not react to a magnet so assume probably Sterling.  The accent stone in the center does react positively to a diamond meter.