Item of the Month: Blue John Tazza

August’s Item of the Month is a rare Blue John miniature tazza, Organ Room vein, Derbyshire, England, circa 1840, on an Ashford black marble base.

Blue John Stone is only found amongst the rocks of Treak Cliff Hill, Castleton. Blue John Stone is now only mined in two caverns: Treak Cliff Cavern and Blue John Cavern. This mineral, a colour banded form of fluorspar, is so beautiful that it has been prized for many hundreds of years.

The origin of the name ‘Blue John’ is thought to have come from the French ‘bleu et jaune’, meaning ‘blue and yellow’. Another theory is that the name ‘Blue john’ was termed by 18th century miners to separate the blue / purple stone from Zinc Sulphites, known locally as ‘black jack’. By the late 18th century, the mineral was much in demand for ornamental vases and columns created for some of the finest houses in Britain, most notably Chatsworth, home of the Duke and Duchess of Devonshire, and Kedleston Hall.