18ct White Gold Blue John 0.25 Carat Diamond Pear Shoulder Ring. R1010. This elegant 18ct white gold ring features a stunning pear shaped hand carved Blue John stone that has been sourced directly from the Treak Cliff Cavern in Castleton, Derbyshire. Sparkling diamonds totaling 0.25 carats embellish the shoulders and frame the stone. All our Blue John jewellery is designed and crafted within our very own workshops in Derbyshire where a team of skilled craftsmen turn the raw Blue John into these stunning pieces of jewellery. You can find other matching Blue John jewellery and other Blue John rings on our website. 18ct White Gold Blue John 0.25 Carat Diamond Pear Shoulder Ring