'Gems of heaven' : recent research on engraved gemstones in late antiquity, c. AD 200-600 / edited by Chris Entwistle and Noël Adams. Entwistle, Christopher. Adams, Noël. British Museum. Gems, Ancient Congresses. Gems, Byzantine Congresses. Precious stones Congresses. Art objects, Byzantine Congresses. NK5555 .G46 2011 553.8 22 SMG Includes bibliographical references. London : British Museum, c2011. c2011. 2011 Text x, 274 p. : eng British Museum research publication, 1747-3640 ; no. 177 Research publication (British Museum) ; no. 177.