Pair of elegant "Blue John" Louis XV vases Violet and beige-coloured veined, so-called "Blue John" fluorite and Louis XV mounting in fire-gilt bronze. Over an open-worked base of opposing leaf volutes, baluster-shaped body with a wide lip rim framed by a profile. Strongly curved side handles of paired volutes and flowers in relief. 1x below collection label "Collection Henri Gautier". H. 17.5 cm. The term "Blue John" is used for a fluorite found in northern England and is derived from the French "bleu et jaune" (blue and yellow). Henri Gautier (1862-1928) was a polytechnician and director of the École de Pharmacie de Paris, as well as a professor of mineralogy, hydrology, toxicology and mineral chemistry. Parts of his collection were auctioned at the Hôtel Drouot, Paris, in May 1929. Provenance: Henri Gautier Collection. A pair of elegant so called Blue John fluorite and gilt bronze Louis XV vases from the property of the French Professor of mineralogy Henri Gautier. England. Circa 1750-1760.