What substance is the basis of the gold refining technique known as 'inquartation and parting' since it can dissolve silver and other base metals but not gold?
Gold parting instead of copper. One part pure gold is alloyed with three parts Sterling silver (inquarting). The resulting six karat (6K) gold can then be parted with dilute nitric acid (one part 68-70% nitric acid to one part DISTILLED water). With the karat gold this low (6K), and over medium high heat, the dilute nitric acid will dissolve the Sterling silver (and other base metals in the karat gold) starting on the outside surface of the 6K gold alloy, working its way into the gold alloy, forming a honeycomb structure as it works its way into the metals. Since nitric acid
Gold parting Here he is describing the heating of gold with salt and iron sulfates which act to dissolve the copper and silver in the gold. Parting vessels used for refining gold with the cementation process have been found in London, Lincoln, York and Winchester. The London vessels, dating from the Flavian period (c.70–85AD), were sealed using luting clay; XRF analysis detected gold and silver, with highest concentration around the sealed region showing possible escape of silver as the volatile silver chloride. Gold parting had been well used throughout the ancient times but only in the Medieval period were clear and detailed