Gold chalcogenides natural occurrence in Maletoyvayam (Kamchatka, Russia) - an experimental approach
Abstract
The Au-Te-Se system was experimentally studied base on a field research performed in the Maletoyvayam ore field at the Kamchatka peninsula located in the Eocene-Oligocene central Kamchatka volcanic belt. Gaching - Maletoyvayam is a high sulfidation type of epithermal deposit where two ternary phases Au2TeSe and Au3Te6Se4 were proved there and characterized in terms of crystal structure, solid solutions, stable associations and thermal stability.
The phase Au2TeSe is stable up to 462 degrees C and the phase Au3Te6Se4 is stable up to 447 degrees C. Experimental results revealed phase relations in the system at 400 degrees C.
The ternary phase Au2TeSe coexists with gold and AuSe, calaverite (AuTe2) and gold, AuSe and Se. The phase Au3Te6Se4 forms stable association with Au2TeSe and Se, Au2TeSe and calaverite, calaverite and gold.
Calaverite dissolves up to 6.7 at. % Se. Coupling mineralogical study and experimental investigations, formation temperature of this Au-bearing mineralization is considered to be below 450 degrees C.