Gold chalcogenides

Gold chalcogenides are compounds formed between gold and one of the chalcogens, elements from group 16 of the periodic table: oxygen, sulfur, selenium, or tellurium.

• Gold(III) oxide, Au₂O₃. Decomposes into gold and oxygen above 160 °C, and dissolves in concentrated alkalis to form solutions which probably contain the [Au(OH)₄]⁻ ion
• Gold(I) sulfide, Au₂S. Formed by passing hydrogen sulfide through solutions of gold(I) compounds.
• Gold(III) sulfide, Au₂S₃, unstable in the presence of water.
• Gold tellurides: Au₂Te₃, Au₃Te₅, and AuTe₂ (approximate formulæ) are known as non-stoichiometric compounds. They show metallic conductivity. Two tellurides of gold are superconductors at very low temperatures: AuTe₃ (2.6 K) and Au₃Te₅ (1.62 K).

Natural gold tellurides, like calaverite and krennerite (AuTe₂), petzite ( Ag₃AuTe₂), and sylvanite (AgAuTe₄), are minor ores of gold (and tellurium). See telluride minerals for more information on individual naturally occurring tellurides.