Whitby Jet Necklace Portrait Marquise Silver. N968. This striking statement necklace boasts an unmissable cabochon oval shaped piece of the finest Whitby Jet stone that has been sourced directly from the north east coast of Yorkshire. The stone is set within sterling silver embellished with the mesmerising foxtail detailing all the way up the chain. All our Whitby Jet jewellery is designed and crafted within our very own workshops in Derbyshire where a team of skilled craftsmen turn the raw Jet into these stunning pieces of jewellery. You can find other matching Whitby Jet jewellery and other Whitby Jet necklaces on our website. Sterling Silver and Whitby Jet.