PRESENT SITUATION OF STUDY ON INVISIBLE GOLD IN SULFIDES

Recently,a great breakthrough has occurred in study on invisible gold with comprehensive test methods using high-reso resolution transmission electron microscope and electron probe etc. Invisible gold means ultramicro and submicro gold present in sulfide in the form of ultramicroinclusion of solid solution. The gold particle is less than lμm in size following Cook et al. Studies on the gold deposits of Canada,Greece and United States show that the sulfide yielding invisible gold is mainly in the gold deposits of Carlin type,hydrothermal type,mas-sive sulfide type and skarn type. The formation of the invisible gold is mostly related with carrier minerals(pyrite and arsenopyrite)and mainly in arsenopyrite. For example,in Carlin gold deposit,gold content is tens to hundreds 10^-6 in pyrite and twice as high in arsenopyrite. The study of invisible gold is significant to both studying ores prolessing te chnology and ore-searching.