Sterling Silver Blue John Cushion Foxtail Stud Earrings. E1840. These unique earrings feature cushions of semi-precious gemstone Blue John. The stones are framed in intricately woven sterling silver foxtail chain and completed with post and butterfly fastenings for secure and easy wear. All our Blue John jewellery is designed and crafted within our very own workshops in Ashbourne, Derbyshire where a team of skilled craftsmen transform the natural Blue John stone into these stunning pieces of jewellery. You can find other matching Blue John jewellery and other Blue John earrings on our website. Dimensions: Blue John stone: 10mm.