http://www.anomalies-unlimited.com/Clamps.html
“Very few of these clamps have survived but analysis of those from Pre-Columbian America show them to be made of a very unusual alloy - 2.05% arsenic, 95.15% copper, O.26% iron, 0.84% silicon and l.70% nickel. There is no source of nickel anywhere in Bolivia. Also the rare alloy of nickel-bronze-arsenic requires extremely high temperatures. The Puma Punks bracket holes, when analyzed, showed platinum, a metal which only melts at 1753 C and aluminium, which supposeedly wasn’t discovered and produced in quantity until the 19th century...”
Stone Technology images on the website.