INFRARED AND X-RAY SPECTROSCOPY OF CLINOC HLORES OF THE KORSHUNOVSKOEDEPOSIT

Composition and structural features of rock-forming and gem chlorites of the Korshunovskoe deposit, Siberian Platform were studied. Both chl orite varieties are close in chemical composition and are Mg-rich clin ochlores. It was established by X-ray diffraction that the rock-formin g chlorite is represented by the commonest polytype IIb with a monocli nic unit cell (beta = 97 degrees), while among the gem samples, along with chlorite IIb, there is chlorite made up of packets of the Ib poly type with a rhombic unit cell (beta = 90 degrees). The IR spectrum of Ib chlorite has considerable differences as compared with the chlorite nb spectrum, owing mainly to weaker hydrogen bonds between layers mak ing up the Ib structural type.