Gold bar found 40 years ago in Mexico was part of a plunder by Spanish conquistador Hernán Cortés

An x-ray machine helped determine the accurate age of the gold bar.

(CNN)Almost four decades ago, a gold bar was found on land that used to be Aztec ruins in Mexico. Now, scientists confirm it was part of a plunder by Spanish conquistador Hernán Cortés.

Scientists have been waiting on technological advancements in order to confirm the date of the gold bar.
"The mexica pieces may have come from the treasure of Moctezuma's ancestors, which the Spaniards found in Teucalco or maybe among the spoils of war stored in royal warehouses in Petlaclaco, gun factories in Tlacochcalco or the crafts workshops in Totocalli," said Leonardo López Luján, an investigator with Mexico's National Institute of Anthropology and History.
He explained that researchers used fluorescent X-ray equipment to analyze the gold bar's chemical composition and match it with other historical pieces discovered in the same area.