Obsidional Coins, or Siege Pieces, as they are generally called, are stamped pieces of metal struck during sieges or by beleaguered cities, when the customary money became scarce. They frequently represent a fictitious value, and a promise of redemption at some future time. The subject cannot be treated here in detail, but conf. Mailliet.
Synonyms: Siege Pieces
Source: Frey's Dictionary (American Journal of Numismatics, Vol. 50, 1916)