The Lycurgus Cup, a cage-cup ( diatreta ) made of dichroic glass, Late Roman Empire, 300s AD. Gilded silver rim and foot were probably added in the late 1700s.
<pre>Information provided by the British Museum : "its glass contains tiny amount of gold and silver which cause it to turn from opaque green to translucent red when light is shone through."
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Room 41, British Museum.
<a href="//commons.wikimedia.org/wiki/User:Vassil" title="User:Vassil">Vassil</a>
<span class="int-own-work" lang="en">Own work</span>