the material was glass and not a gemstone, which had previously been in question. It seems likely that as many as three separate workshops or factories were involved in the production of the cup, perhaps not in the same part of the Empire. The glass may have been initially made in a large block of standard clear glass, perhaps in Egypt or Palestine, which both exported great quantities of glass for forming, and sometimes colouring, elsewhere. The thick "blank" dichroic vessel was probably made by one specialist workshop and passed to another consisting of specialist cutters. This would certainly have been a rare and highly expensive object, and the secrets of its manufacture, possibly not well understood even by its makers, seem only to have been used for about a century. There are various small losses, of which the face of the panther is the most significant, and the cup is cracked; the British Museum has never removed the metal rim for this reason. The base or foot of the cup is damaged, and the original form of the base uncertain. The Metropolitan Museum of Art, in New York, has a fragment measuring 2 3/16 × 3 in. (56 × 76 mm) of a satyr from a dichroic cage cup that turns from olive green to "reddish amber". Modern recreations Corning Glass Works has reproduced a blank of a material of similar chemical composition and internal structure, which displays under reflected and transmitted light the same "Lycurgus effect" of green to red colour change as the Lycurgus cup material does. Cranberry glass or gold ruby glass is somewhat similar and far more common, manufactured with colloidal gold, but this only ever shows a red colour. Recently, researchers from The Netherlands have been able to reproduce the green/red dichroic effect in a 3D printable nanocomposite material. This effect, like in the original Lycurgus cup is due to small amounts of silver and gold nanoparticles, of the proper size and shapes, embedded in the 3D printable material. Iconography The figure of Lycurgus, bound by the vine and naked apart from boots, is flanked on the left by a crouching Ambrosia, at a considerably smaller scale. Behind her one of Dionysus's satyrs (shown with a normal human form) stands on one foot as he prepares to hurl a large rock at Lycurgus. In his other hand he holds a pedum or shepherd's crook.