New occurrences of hessite, petzite and stützite at Coranda-Hondol open pit (Certej gold-silver deposit, ROMANIA)
Andrei Ionut APOPEI1,*, Gheorghe DAMIAN1,2, Nicolae BUZGAR1, Stanislava MILOVSKA3 & Andrei BUZATU1
1“Alexandru Ioan Cuza” University of Iaşi, Faculty of Geography and Geology, Department of Geology, 20A Carol I Blv., 700505 Iaşi, Romania, *e-mail: email@example.com
2Tech Univ Cluj Napoca, North University Center of Baia Mare, 62A Dr. Victor Babeş Street, 430083 Baia Mare, Romania.
3Geological Institute, Slovak Academy of Sciences, Severná 5, 974 01 Banská Bystrica, Slovakia.
Au-Ag- and Ag-tellurides are widely abundant in the vast majority of the “Golden Quadrilateral” (Metaliferi Mts., Romania) ore deposits. Optical microscope observations, electron microprobe and μ-Raman analyses have been successfully carried out to identify Au-Ag-Te minerals from Coranda-Hondol open pit (part of Certej deposit, South Apuseni Mountains, in Romania). The identified tellurides are hessite (Ag2Te), petzite (Ag3AuTe2) and stützite (Ag5-xTe3, where x = 0.24-0.36) and they usually occur as patches (reaching 90-100 μm in length) in galena, bournonite-seligmannite or at the contact between the last three minerals. In general, all the microanalytical data are stoichiometric with a slightly compositional variation in the case of hessite. The μ-Raman spectrum of stützite shows a characteristic Raman fingerprint with a very strong band at 147 cm-1. The broadness of the Raman band (147 cm-1) indicates a non-homogeneous distribution and, in conjunction with the strong heterogeneity observed under microscope, it suggests that the tellurides have formed contemporaneously and they can possibly be attributed to a later silver-rich telluride-bearing substage.
Keywords: Certej, Coranda-Hondol, tellurides, hessite, petzite, stützite, EPMA, Raman spectroscopy