FORMS OF SILVER OCCURRENCE IN ALUMINOSILI CATE GLASSES

Experimental data have been presented on the state and migration prope rties of silver in aluminosilicate glasses in different temperature an d oxygen fugacity regimes, Oxidation state of silver in glasses of gra nite eutectic composition has been determined by means of EPR techniqu e. These glasses were prepared within wustite f(O2) stability field, h eat-greated at 500 degrees C in air as well. Absence of silver EPR res ponse in as-prepared and heat-treated samples as well as appearance of a signal in heat-treated samples where Ag-0 was stabilized by X-rays allows us to assume atomic silver in as-prepared samples and oxidation to Ag+ during heating. It has been stated that silver mobilization fr om the glasses of basaltoid composition increases one order of magnitu de with changing temperature and f(O2) regimes, This can cause increas ing ore-generating ability of volcanic rocks at the postmagmatic stage .