Gold element silver (as electrum) and also naturally alloyed with copper and palladium. Less commonly, it occurs in minerals as gold compounds, often with tellurium (gold tellurides). Gold is resistant to most acids, though it does dissolve in aqua regia, a mixture of nitric acid and hydrochloric acid, which forms a soluble tetrachloroaurate anion. Gold is insoluble in nitric acid, which dissolves silver and base metals, a property that has long been used to refine gold and to confirm the presence of gold in metallic objects, giving rise to the term "acid test". Gold also dissolves in alkaline solutions of cyanide,
Metal Gear Acid Metal Gear Acid , stylized as METAL GEAR AC!D, is a turn-based collectible card tactical RPG video game developed by Konami Computer Entertainment Japan for the PSP handheld game console. The game was first unveiled at E3 in May 2004, and was released in Japan on December 16, 2004, in North America on March 22, 2005, and in Europe on September 1, 2005. It was the first game in the "Metal Gear" series for the PSP. A Java ME version for mobile phones was released by Glu Mobile in titled "Metal Gear Acid Mobile". "Acid" focuses on turn-based tactics, using