[Paal Gulli]

"...The greatest valuable single object that had ever been discovered from a shipwreck, was ‘Tucker’s Cross’. It was discovered by Bermudan diver, Teddy Tucker. The cross was made of 22-karat gold, with seven emeralds as big as musket balls....

That's a curious statement to make, considering they didn't back it up (at least not outside the paywall) with an estimated value. Even the Wikipedia page fails to mention the object's weight, or how much 22K gold is in it, or the estimated worth.

[SunkenCiv]

A couple million, if memory serves.