Sterling silver blue john marcasite eyes owl necklace p2325 this charming necklacefeatures hand carved marcasite and round shaped blue john which has been sourced directly from the derbyshire blue john cavern in castleton the highly polished blue john is framed within a quirky sterling silver owl design with the pendant being presented on a 18 sterling silver chain and completed by a classic bolt ring clasp for easy wear all our blue john jewellery is designed and crafted within our very