Hydrothermal Sphalerites from Ore Deposits of Baia Mare Area

Sphalerite is an abundant mineral in the hydrothermal deposits from the Baia Mare and Oas areas (northwestern Romania). Sphalerite samples were analyzed with an electron probe microanalyzer and Raman spectroscopy. The obtained results indicated different amounts of Fe in the various deposits from the Baia Mare and Oas areas. The sphalerites from Baia Sprie, Cavnic, Iba, Turx21b; Penigher, and Breiner have a low Fe wt.% content. High Fe wt.% contents are at Herja and partly at Ghezuri and Nistru (copper stage) where sphalerite is associated with pyrrhotite. The correlation between iron and zinc from sphalerites is strongly negative. The negative correlation shows that iron is the main element that replaces zinc in the sphalerite structure. The manganese content of sphalerites in the Baia Mare and Oas area is up to 0.84 wt.%. The cadmium content is quite uniform in the Baia Mare and Oas area with contents ranging from 0.01 to 0.72 wt.%. The Fe content of sphalerites is an important indicator of the physico-chemical conditions of deposit formation because it is a function of temperature, pressure, and sulfur fugacity.