PRELIMINARY INVESTIGATIONS OF GOETHITE AND MONAZITE FROM SIVEC, REPUBLIC OF NORTH MACEDONIA

Abstract

This paper presents the preliminary investigations of goethite and monazite that appear in marbles from Sivec. The presence of these minerals was not previously reported in the Sivec marbles that, along with the dominant dolomite and calcite, also revealed the presence of a vast number of other minerals including fluorite, rutile, phlogopite, corundum, diaspore, almandine, clinochlore, muscovite, quartz and zoisite. Goethite [Fe3+O(OH)] from Sivec occurs in small crystals found generally in finegrained parts of the white dolomitic marble. The color ranges from yellow-brown to nearly black, and the luster varies correspondingly from earthly to submetallic. Cleavage is perfect {010} and less perfect {100}. The streak is yellowish brown. Тhe size of the goethite crystals is 1 cm. The crystal system is orthorhombic. Point Group: 2/m 2/m 2/m, Space Group: Pbnm. The unit cell parameters obtained using the strongest Xray diffraction peaks are: a = 4 .617 Å, b = 9.976 Å, c = 3.024 Å, Z = 4, V = 139.32 Å3. Мonazite crystals are found on the surface of the goethite crystal. The size of the crystals within size varies in length (21.88 – 53.61 μm) and width (8.45 – 20.38 μm).
Key words: Sivec; marble; goethite; monazite