Aqua Regia

Aqua regia ( "royal water"), aqua regis ( "king's water"), or nitro-hydrochloric acid is a highly corrosive mixture of acids, a fuming yellow or red solution. The mixture is formed by freshly mixing concentrated nitric acid and hydrochloric acid, usually in a volume ratio of 1:3. It was named so because it can dissolve the so-called royal or noble metals, gold and platinum. However, titanium, iridium, ruthenium, tantalum, osmium, rhodium and a few other metals are capable of withstanding its corrosive properties.

Read more about Aqua Regia:  Applications, History

Other articles related to "aqua regia":

Aqua Regia - History
... Aqua regia first appeared in the work of medieval European alchemist Pseudo-Geber, dating from the 14th century ... Max von Laue (1914) and James Franck (1925) in aqua regia to prevent the Nazis from confiscating them ...
Noble Metals - Introduction
... platinum, gold and mercury can be dissolved in aqua regia, a highly concentrated mixture of hydrochloric acid and nitric acid, but iridium and silver cannot ... (Silver can dissolve in nitric acid, though.) Ruthenium can be dissolved in aqua regia only when in the presence of oxygen, while rhodium must be in a fine pulverized form ... tantalum are resistant to acids, including aqua regia ...