Stones and crystals from Mount Vesuvius, c 1770.

Hand-coloured etching by Peter Fabris (active 1768-1779). Illustrated plate from William Hamilton's study of Italian volcanoes, 'Campi Phlegraei' (published in Naples, 1776). Fragments of stones and crystals collected in the region of Vesuvius by Hamilton, including (9) a brown-coloured crystal called Jacinth, (11) striped marble and (12) so-called partridge-eyed lava, like that found under the city of Pompeii. Hamilton's book is a seminal study of the nature and effects of volcanic activity.