Mineralogical characterization of chrysotile from Bogoslovec, North Macedonia

Abstract

This paper presents the results of an investigation of mineralogical and chemical characteristics of
chrysotile from Bogoslovec locality. Investigated samples were analyzed by SEM-EDS and XRD methods. Chrysotile is a member of the serpentine group, occurring in bundles of parallel finers, with random orientation about the finer axis. Chrysotile occurs as compact veins in the serpentinites. Sometimes finer veins split up in several smaller veins or coalesce and form a larger vein. The fibers are oriented perpendicular to the vein walls. Individual chrysotile finers are white and silky, but the colour of the aggregate in veins is usually light yellow to light green. Chrysotile veins are wide up 99 μm to a few millimeters. The development of chrysotile veins illustrates the mobility of the major elements Mg, Fe and Si during serpentinization. Тhe luster is silky. Crystal system is monoclinic, point group 2/m. Streak is white. Fibrous crystals of chrysotile from Bogoslovec are with different size (long from17 to 390 μm and width from 0.35 μm on individual fibers and 30 μm on bundles). In examined samples from Bogoslovec have substitution of Mg2+→Fe2+. Concentration of Fe 2+ is in range up 0.52 to 2.68 wt%. The unit cell parameters obtained using the main reflection lines of X-ray diffraction are: a = 5.330 Å; b = 9.156 Å; c = 14.665 Å; β = 93.432°; V = 714.550 Å3