Mineralogical characteristics of kyanite from Prilepec, Republic of Macedonia

Abstract

This paper gives mineralogical characteristics of kyanite from village of Prilepec, R.Macedonia. Several samples were collected for research. The kyanite was identified by Scanning electronmicroscopy (SEM), coupled with an energy dispersive X-ray spectrometer (EDS), X-ray diffraction(XRD) and Infra red spectroscopy (IR). The use of these three methods showed that they are very usefulmethods for rapid mineral analysis contributing important analytical information.The results of the X-raypowder pattern, SEM analysis and Infra red spectroscopy enable straightforward identification of thestudied mineral sample as kyanite. Kyanite is located east of village of Prilepec in micashist rocks whichhave lepidoblastic structure and schistose texture. It occurs in blue thin-bladed triclinic crystals and crystallineaggregates. Cleavage is perfect on {100}, good on {010}. Fracture is splintery. Kyanite is transparentto translucent. Lustre is vitreous or sub-vitreous. Hardness lengthwise 4–5, crosswize 6–7. Density3.53–3.67 g/cm3 .The colour is blue. Origin on blue colouris due to the charge-transfer process Fe2+ →Fe3+, Fe2+ Ti4+ or Cr3+. In our samples concentration of Fe is 0.05–0.18 wt%, Ti concentration is 0.03–0.11 wt%, while Cr concentration is 0.02–0.13 wt%.