During the investigation of solders on ancient gold artifacts found in Iran and Syria, cadmium was found at a concentration up to several per cent. Careful interpretation of relative concentrations of copper, silver, and cadmium in those solders easily enables discrimination between brazing of modern and ancient origin, and forms a simple criterion of identification. Experimental archaeology corroborates this. We suggest a new interpretation of Book XXXIII of Pliny the Elder on the soldering of gold: the chrysocolla of the goldsmith, gold solder, could be greenockite (natural cadmium sulfide), and not necessarily malachite (natural copper carbonate). -- AATA