Sterling Silver Blue John Triangle Knot Celtic Necklace. P261. This elegant necklace features hand carved Blue John that has been sourced directly from the Derbyshire Blue John Cavern in Castleton. The highly polished Blue John gemstone is framed within a unique sterling silver Celtic design with the pendant being presented on a 18\" sterling silver chain. The necklace is completed with a classic bolt ring for 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 stylish pieces of jewellery. You can find other matching Blue John jewellery and other Blue John necklaces on our website. Dimensions: Pendant 24 x 28mm, Blue John 8mm in diameter.