once alone on the island, how does Dantes un earth his treasure?

Dantes slips and feigns a serious injury, one that will not allow him to be moved back to the ship with the smugglers. Instead, the ship leaves to complete the smuggling expedition and agrees to soon return to fetch him. Dantes is thus left alone on an uninhabited island to search for the treasure. He excavates and finds a wooden chest bound with iron. When the lid opens precious stones are revealed. Dantes is dumbfounded, but it is not a dream. Dantes prays to God.

http://www.gradesaver.com/the-count-of-monte-cristo/study-guide/section2/

Otis's link.