About 200 gold and silver funerary ornaments from the Moche tombs “Señor de Sipán” and “Señora de Cao” were analyzed to determine their metallurgic characteristics. Of particular interest was the question about the gold-silver joining process. To this aim, following methods were employed, all based on the use of X-rays: -energy dispersive X-ray fluorescence; -transmission of monoenergetic fluorescent X-rays; -radiography. At least three joining methods were possibly identified: -of gluing gold and silver sheets; -of brazing using a proper solder; -of using a mercury amalgam.