Aurous thiosulphate

Aurous thiosulphate, Au2S203,3H2S203,H20.—This substance is to be regarded as a complex aurothiosulphuric acid. It is prepared by the action of dilute sulphuric acid on the barium salt.4... 

Gold carbide, Au2C2.—A solution of aurous thiosulphate reacts with acetylene, precipitating a very unstable, highly explosive carbide.6... 

Aurous cyanide forms yellow, microscopic laminae, very slightly soluble in Water. It is more stable than aurous iodide, but at red heat is decomposed into gold and cyanogen. Its insolubility renders it immune to the action of dilute acids and hydrogen sulphide, but solutions of ammonia, potassium hydroxide, ammonium sulphide, and sodium thiosulphate dissolve it, probably forming complex derivatives. In aurous cyanide the tendency to form complex compounds is much more marked than in the corresponding chloride, bromide, and iodide.3 Its interaction with potassium ferrocyanide has been studied by Beutel.4... 

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