The inclusion of gold in accessory zircon of the Kozhim granitic massif

The crystals of zircon can reveal information about their formation environment due to their resistance to external influence and also inclusions observed of them. Zircon can contain different mineral inclusions: biotite, plagioclase, quartz, аpatite, etc. However no information about gold inclusions has been available in the zircons from granites of the Sudpolar Urals. The study results of the inclusions of gold in accessory zircon of the Kozhim granitic massif are presented in this paper. The studied mineral is a dark-brown translucent short-prismatic crystal containing an inclusion of gold and nodules of quartz. According to our studies, the inclusion of gold formed during the growth of zircon and it is gold covered with a thin film of oxide gold. It was confirmed that the crystallization of the studied zircon occurred at a temperature of 800 °С and above at the stage of formation of granites of Kozhim massif. We suggested the presence of an additional temperature mode when the temperature decreased to 700 °C and below during the postmagmatic stage.