A Fine Derbyshire Blue John Tazza on a Tall Knopped Stem and Spreading Tiered Foot, Early Century - Blue John, a type of fluorspar, is unique to Derbyshire and has been valued for its beauty and colour for hundreds of years. Pliny writing in the
A small English Blue John Tazza century the black slate plinth supporting a circular molded pedestal supporting a spreading circular foot and stem surmounted by a bowl with molded collar and molded rim. height 6 in. diameter 3 in.