These metals consist of ferrous metals and alloys. The ores of base metals are often sulfides. The important industries are paper manufacturing, basic metals and alloys, and machinery. Caesium forms alloys with the other alkali metals, gold, and mercury (amalgams). Such alloys have some of the best properties of metals and ceramics. Different estimates exist of the amounts of indium contained within the ores of other metals. Bismuth will behave similarly with another of its major metals, copper. Oxides of most metals adopt polymeric structures. Superoxide forms salts with alkali metals and alkaline earth metals. Cermets are ceramic particles containing some metals. Controlling the quantity of these metals improves corrosion resistance. Graphite forms intercalation compounds with some metals and small molecules. Assaying is analysis of the chemical composition of metals. Russia also contains most of the nonferrous metals. Gold is the most malleable of all metals.