Pair of cups in Blue John with a turned stem, resting on a circular plinth and a low quadrangular base.
Dimensions: h 17 cm; diameter: 16 cm ( 6,7 x 6,3 in )
Blue John is a semi-precious mineral, a particular type of fluorite that has the characteristic blue-purplish and yellowish bands. It became especially popular during the 19th century, when it became widely used in the production of vases and cups for ornamental purposes.
If there are numerous furnishings made of blue john, the cup shape is particularly rare and rich on the market.