Silver Turquoise Marcasite Round Ring. R747. This petite, feminine Sterling Silver, Turquoise and Marcasite ring features a circular central piece of Turquoise, which is the December birthstone. The striking stone is surrounded by sparkling pieces of Marcasite and set on a classic silver band. All our Turquoise jewellery is designed and crafted within our very own workshops in Ashbourne, Derbyshire where a team of skilled craftsmen turn the raw Turquoise stone into these stunning pieces of jewellery. You can find other matching Turquoise jewellery and other Turquoise rings on our website. Silver Turquoise Marcasite Round Ring. Turquoise 3mm diameter, top of ring including Marcasite 9mm diameter.