The dragon's hoard is buried with Beowulf's ashes.
After the dragon is killed, Beowulf tells Wiglaf to look for the dragon's treasure and to bring it to him. Beowulf feels that death will be easier to bear if he can look at the treasure with his own eyes. He wants his people to have the treasure, noting that his death will not be in vain if his people can profit from the fruits of his death.
When Wiglaf enters the dragon's tower, he sees piles of gold, precious gems, and priceless tableware strewn about. He takes what he can back with him to Beowulf, making haste lest Beowulf should die before he sees what he has won. When Beowulf sees the treasure, he thanks God for it and proclaims that he has sold his life well for the treasure. Before he dies, Beowulf gives Wiglaf his golden necklace, rings, mail shirt, and gold-covered helmet.
After Beowulf dies, his followers show up. Wiglaf excoriates them for their cowardice in leaving their king to fight the dragon by himself. He tells them that they will not have the treasure, because they have disgraced themselves. So, the warriors end up building Beowulf his funeral pyre and burying the dragon's hoard with his ashes.
They placed in the barrow rings and jewels,
Rings and gems are laid in the barrow.
All such ornaments as erst in the treasure
War-mooded men had won in possession:
The earnings of earlmen to earth they entrusted,
The gold to the dust, where yet it remaineth
As useless to mortals as in foregoing eras.