In the Georgian and Victorian periods, wealthy people undertook tours of Italy, Egypt and Greece, in particular to admire Roman ruins and Renaissance architecture. They tried to purchase souvenirs from each place they visited. In Rome, they usually purchased micro mosiac jewellery

micromosiac ringIMG_2522
Victorian micro mosiac ring (personal collection)

and in Florence, it was pietra dura items.

Pietra dura locketI frontMG_7201s
Victorian pietra dura pendant (sold)

Pompeii was a popular destination for these wealthy tourists and jewellery was sold that was supposed to contain lava from Mount Vesuvius. The lava came in muted brown, grey, greens, ochre and cream, and skilful artists carved and polished beautiful cameos which were turned into bracelets, brooches, pendants, earrings and necklaces. The carvings were usually of classical heads or great Italian artists or writers. As the stone is quite soft, the cameos are usually carved in high relief which means they can suffer from damage over time.

cameo lava ring
Antique lava and coral cameo ring in 9ct rose gold (on Ruby Lane)
Lava brooch
Antique lava cameo brooch, with matching earrings (on Ruby Lane)