The Maltese Falcon is a figurine given by the Knights of Malta to the King of Spain, encrusted with jewels but lost at sea. Over the years, it was covered with a coat of black enamel. Like Russia's Amber Room or Spear of Longinus, it is considered a treasure of unusual value. The figurine gave a title to a fictionalized exploit of detective Sam Spade, written by Dashiell Hammett.
Spade, and by inference the Maltese Falcon, were referred to by Philip José Farmer in Doc Savage: His Apocalyptic Life.