This Queen Helmet shell is a virtuosic example of nineteenth-century shell cameo carving. The engraver, using chisels, drills and abrasives, worked inwards from the surface, retaining or removing material until the decoration slowly emerged. Layers of contrasting colours occurring naturally within the shell were skilfully used to create illusive depth in the ornament. The art of gemstone carving was known in ancient Greece and Rome, and revived in Renaissance Italy when connoisseurs began to form rich collections of engraved stones. Shell cameos, which were cheaper and more easily worked, became fashionable in the nineteenth century and were acquired as Grand Tour souvenirs.