ABSTRACT: The Technology and the Metallic-ore Departments of the Mineral. .Research, and Exploration Institute (MTA) investigated the heavy mineral concentrates- of the gold-bearing upper, gray coloured conglomerates which occur in, the Izmir, Salihli-Sart area,, The following heavy minerals as well as gold, and gold-amalgemetes have been identified under` the microscope within these concentrates. a) .Sulfides: Pyrite, Marcasite, Chalcopyriie, Cinnabar, Sphalerite,», Pyrrhotite, Tennantite- ltetrahedrite, Arsenopyrite, Galena, Barnite* Covellite, Realgar,. b) Oxides: Magnetite+Ümeno-Magnetite» Rutile+Anatase, Hematite+ÎIineno-Heinatite, tlmenite^,, Chromite, Spinel» Pyrolusite., c) Phosphates Apatite« The dectron micropro`be studies of gold grains» which show various tones of colour under . the microscope, indicate that besides gold they contain, such metals as silver, bismuth, mercury, thulium.» iridium, copper, germanium, osmium and iron. Gold usually occurs as an amalgamate with these elements. The results of semi-quantitative o;ptic spectrographic .analyses indicate `the presence of tin, in `the range of 300-700 ppm., in. the heavy mineral concentrates of the Salihli-Sart cong- , lomerates., Various fractions of these heavy mineral, concentrates, which, are enriched, in their rutile contents» have been .analysed and studied under the microscope,., Tre results of the semi-quantitative analyses show that tin, is. closely related `with the titanium content `Of rutiles. `Therefore it is- concluded that tin. is emplaced within the crystal structure of rutiles.