Rare Find Vintage CMC 12k Gold Filled Black Onyx Pendant & Necklace

It is a very unique Victorian 12/20 Gold Filled Black Onyx Pendant & Necklace. - Necklace length: 19 inches - Pendant length: 2&3/4 inches - Stone size: 15 x 10mm - Weight: 7.13 grams. CMC is a trademark of Curan Myers, Carleton Jewellery Company in Boston MA, US, Era C.1943. 12/20 Gold Filled means that 1/20 of the metal weight of this bracelet consists of 12K Gold