18ct Yellow Gold Whitby Jet Small Cushion Signet Ring, R191. This classic signet style ring features a hand carved oval Whitby Jet gemstone, which is inlaid into a thick band of solid 18ct yellow gold. Because the Whitby Jet is inlaid within the yellow gold this creates a beautiful smooth finish and a brilliant shine. Dimensions: Whitby Jet; 10mm x 8mm, Width of band; 3.5mm. All articles Purchased from C W Sellors are lovingly and securely dispatched with our elegant jewellery packaging. Matching items also available within this collection.