When the mythical island of Atlantis submerged into the ocean, it took all of its orichalcum with it. The legendary cast metal was reputedly second only to gold in value. Now, a team of divers say they’ve recovered 39 blocks of orichalcum in a sixth-century shipwreck on the seafloor near Sicily, Discovery News reports. The 2,600-year-old ship, likely from Greece or somewhere in Asia Minor, was carrying the metal to Gela in southern Sicily when it was caught in a storm and sank around 300 meters (1,000 feet) from the port.

"Nothing similar has ever been found," Sebastiano Tusa of Sicily's Sea Office says. "We knew orichalcum from ancient texts and a few ornamental objects." According to Plato’s Critias, the metal was mined only on Atlantis, where it was used to cover the inside of Poseidon’s temple.

Experts nowadays agree that orichalcum is a brass-like alloy that was made in that past by reacting zinc ore, charcoal, and copper metal. When the newly discovered ingots were analyzed with X-ray fluorescence, Discovery explains, the metal turned out to be an alloy made with 75 to 80 percent copper, 15 to 20 percent zinc, and small percentages of nickel, lead, and iron.

Tusa’s team is now working on excavating the entire shipwreck, which may reveal more about artisan workshops in antiquity.