This gorgeous and well marked antique by, B H Britton & Sons (1921) 9k rose gold curb link watch chain has been gloriously repurposed into a necklace. Dangling from the center is a 1911 22k gold Sovereign coin pendant. 

ID#: NEC322

Metal: 9k rose gold 

Length: 15 3/4 inches 

Chain Weight: 38.42g

Total Weight: 46.40g

Markings: '9', '375', 'B&S', Anchor (Birmingham), 'W' (Date letter - 1921)

Coin: 1911 Gold Sovereign King George V

Metal: 22k yellow gold

Weight: 7.98g

Dimensions: 22.05mm diameter