Atocha Shipwreck Copper - Ingot Slice #26 - Weight 468 grams

Description: Slice of Atocha Copper from Ingot # 85A-1625-2

Recovery date: 12/31/1985

Size: Height: 3.0 " Length: 8.75" Thickness: 4.71mm

Origin: Cuba

Weight: 468 grams Number: 26 of 35

History: The Cuban mine at Caridad de Cobre produced 582 Royal copper ingots that were used as ballast on the Atocha. The mine itself was owned by the Spanish Crown, and only three ships in the 1622 Fleet carried the Royal copper cargo. The Atocha, the Santa Margarita, and Nuestra Senora del Rosario, were designated with this honor, and were loaded with the precious cargo in Havana Harbor, Cuba. This immense cargo, 30,000 pounds, specifically, was nestled neatly near the stern on the Atocha, located immediately behind the mainmast in the lower hold. Just forward of the mainmast lay the stacks of silver bars and masses of coin chest, which were also used as ballast.

Upon arrival to Spain, the copper was intended for the manufacturing of bronze cannons, similar to those recovered on the Atocha site. In stark contrast to the marked silver ingots, these Cuban copper ingots did not bear any Assayer Marks or Mint Marks – rather, they were completely unmarked, and crudely cast by pouring modern copper ore into simple depressions in the ground.

According to a random sample survey of 50 Atocha copper ingots found previously on the site, each ingot weighed on average 54.2 pounds. Comparatively, this copper ingot weighed 63 pounds before slicing, and is roughly the same size and density as a coin chest on the Atocha.