A silver cup is an item in Evony TKR (The King's Return).
Silver Cup is one of the collection items in the exhibition for the Art Hall. It is one of four parts in the Cup Hall. After the set is completed at three stars, you can trade additional Silver Cup fragments for gold.
The description of Silver Cup in Evony TKR says:
Cups made from different textures. The important exhibits in Cup Hall.
Silver Cup is known to potentially be obtainable from opening Artwork Fragment Chest IV, Artwork Fragment Chest V and Artwork Fragment Chest VI. The links for each item are below:
Note: This list may be incomplete.