Silver oxalate is a chemical compound of silver. It is used in experimental petrology to add carbon dioxide to experiments. Silver is a metallic element with the chemical symbol Ag and atomic number 47. It occurs naturally in its pure, free form, as an alloy with gold and other metals, and in minerals such as argentite and chlorargyrite. Silver oxalate, one of the coordination polymer crystals, is a promising synthetic precursor for transformation into Ag nanoparticles without any reducing chemicals via thermal decomposition of the oxalate ions.