wizyta

od 2020-09-20

Title: ICP, IR, Raman, NMR investigations of beryls from pegmatites of the Sudety Mts

Source: Journal of Molecular Structure

Year : 2005

Abstract:

Detailed ICP, IR, Raman and NMR investigation were performed for more than 50 samples of beryls from pegmatites in the Sudety Mts. MIR spectra were measured at room (293 K), low up to 22 K and high up to 1273 K temperatures. The absorption bands for studied samples of beryl are correlated with chemical composition and structural parameters. The samples represent both alkali-poor (potassium-bearing, sodium-potassium-bearing) and alkali-rich (sodic and sodic-lithian) members of the beryl group. Two types of H2O molecules are discerned in all studied beryls. The I-type is not connected with alkali with bands at 3697/3690 cm(-1), 3647/3630/3610 cm(-1) (3606 cm(-1) in Raman spectra) and 1602/1550 cm(-1) dominates over the II-type (hydrated anions of alkali) with bands at 3660 cm(-1), 3592/3590 cm(-1) (3597 cm(-1) in Raman spectra) and 1637/1630cm(-1). CO2 molecules (2360 cm(-1) in MIR spectra, 1386 cm(-1), 1240 cm(-1) in Raman spectra) and hydroxyl groups in subordinate quantities occur in structural channels of beryls, except for mentioned above. Main bands in the range of 1200-400 cm(-1) are diagnostic in discerning of the three types of beryls according to lattice parameter classification. Studied beryls, in the most cases, belong to normal-type. Some samples are octahedral-type, and do not occur tetrahedral beryls in the Sudety Mts.
(C) 2005 Elsevier B.V. All rights reserved.

DOI: 10.1016/j.molstruc.2004.12.042   (Pobrane:  2020-10-21)