A mythical mass of gold and precious stones, which Siegfried obtained from the Nibelungs, and gave to his wife Kriemhild as her marriage portion. It was guarded by Albric the dwarf. After the murder of Siegfried, his widow removed the hoard to Worms; here Hagan seized it, and buried it secretly beneath “the Rhine at Lochham,” intending at a future time to enjoy it, “but that was ne'er to be.” Kriemhild married Etzel with the view of avenging her wrongs. In time Günther, with Hagan and a host of Burgundians, went to visit King Etzel, and Kriemhild stirred up a great broil, at the end of which a most terrible slaughter ensued. (See Kriemhild.)
'T was much as twelve huge waggons in four whole nights and days Could carry from the mountain down to the salt sea bay; Though to and fro each waggon thrice journeyed every day. It was made up of nothing but precious stones and gold; Were all the world bought from it, and down, the value told, Not a mark the less would there be left than erst there was I ween.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894