Sunken Treasure, Mint Condition
On Friday, a team of deep-sea treasure hunters announced the discovery of a shipwreck containing 17 tons of Colonial-era coins worth as much as $500 million. The team’s sponsors haven’t revealed where in the Atlantic they recovered the cache or what ship carried all of that loot. They did, however, note that the gold and silver coins were in pretty good condition. What factors affect the quality of shipwreck coins?
Where the ship goes down and what kind of metal the coins are made of. Coins that spend hundreds of years submerged can end up getting scratched, worn down, corroded, covered by sea life or lime deposits, or damaged by acid conditions. The warm waters of the Caribbean and the tropics are likely to cause the most damage, as warmer temperatures speed up oxidation and corrosion. These waters also contain coral and micro-organisms that can encrust the coins, depleting their value, usually permanently. Cooler northern seas – like those off the coast of England, where some speculate this treasure was uncovered – are more likely to help keep all kinds of coins looking good.
The National Geographic chimes in on the debate, saying the fate of the treasure is a toss up.