Report on Mineralogical Examination of samples 5115-2, 5215-8, 5225-15, 5300-2, 5310-19, 5390-10, 5425-15, 5440-7, 5440-8A, S1054, S1130WI, S1134, S1134W2, S1134W3, S1134W5, S1136W1

Abstract

1) 20 samples of drill core were received for mineralogical examination. The aim of the examination was to characterize the major chemically distinguishable ore types in terms of mineralogical composition, ore texture by means of an optical microscope and by scanning electron microscope GeoSEM. 2) The sulphide mineralisation appears visually 'massive' even when microscopic examination indicates abundance of non-opaque minerals. 3) Pyrite, sphalerite, galena, boulangerite, falkmanite, bournonite and arsenophyrite are the major ore minerals present in the examined samples. 4) Lead is present as galena, boulangerite, falkmanite and bouronite implies that there will always be a small amount of copper in the lead concentrate. 5) Zinc is present predominantly as sphalerite. 6) Silver is present as freibergite, argentian tetrahedrite and as unidentified Ag-Pb-Sb-S and Ag-Sb-S minerals. 7) Trace amounts of Co-Ni mineral (gersdorffite, cobaltite, ullmanite), cassiterite and a stannite-like Cu-Sn mineral were found only by means of GeoSEM. 8) Four major and three minor assemblages of ore minerals can be distinguished in the examined material. 9) The character and paragenetic relationships of the assemblages appears to be the same in all examined sections. 10) The sequence of formation of the major minerals appears to be; pyrite (+or - arsenopyrite) - sphalerite - Pb-Sb minerals (galena, boulangerite, falkmanite, bournonite). The paragenetic position of the minor assemblages is uncertain. 11) Most samples contain more than one material assemblage. The Pb, Zn, etc., content in a sample depends on the relative proportions of the individual assemblages within the sampling interval. This could be best assessed by detailed visual inspection of the core. Assessment based on a few randomly or deliberately selected polished sections could be misleading. 12) The non-opaque rock-forming minerals and non-opaque minerals associates with sulphide mineralisation have not been examined in any detail, their indentification is incidental.