OK, here are the facts, right from the horses mouth: When I was working the Atocha at "Emerald City" I asked Mel Fisher about the source of the emeralds. There were no emeralds listed on the ships manifest so they were obviously being smuggled to Spain without paying tax. Mel's researcher found a letter in the archives from a count on King Philip's court to one of the crew salvaging the Margarita. It said "keep watch for emeralds that belonged to Count..... There are two chests weighing 79 pounds."
The captain of the supply ship sailing from Spain to Havana would open everybodys mail and read it. When he saw this letter he reported it to King Philip. The King had the Count arrested and hanged him, his wife and children! So there is no "barrel" of emeralds. They were contained in two chests weighing 79 pounds. At the time (1994), Mel and his crew found a total of 5 pounds of emeraldes so there is much more still out there.