Georgian Baccante Lava Cameo Brooch half hoop the gemstone was used by

the gemstone was used by chemists to polarize light by shining rays onto a cut facet of the stone

It was made by hand circa 1820

Of the exceptionally high quality you'd expect from a Russian piece of this era

Jewellers & Goldsmiths to the Queen and Royal Family"

and set with rose cut diamonds

Georgian Baccante Lava Cameo Brooch half hoop the gemstone was used byDATE: Georgian, c. 1820 A cool Georgian lava cameo brooch dating from the early 19th century, circa 1820. The subject is a Baccante with characteristic ivy leaves worn in the hair (also confirmed by an inscription on the back of the cameo). Carved from a single piece of gray green Mount Vesuvius lava, it will have been brought back by a Grand Tourer to commemorate (presumably suitably hedonistic) time spent in Rome. The detail is excellent, carved in