THE MORPHOLOGY OF SOME HYDROTHERMALLY SYNTHESIZED LI-MINERALS - A-ZEOLITE, ALPHA-EUCRYPTITE, BETA-SPODUMENE AND BETA-EUCRYPTITE

The hydrothermal treatment of glass with the composition 2 LiF, Al2O3, 3 SiO2 at 1 kbar in the range of 150-degrees-C to 850-degrees-C gave rise to the formation of A-zeolite with orthorhombic unit cell with a = 10.31 angstrom/b = 8. 18 angstrom/c = 5.0 angstrom (space group Pna2(1)), alpha-eucryptite, trigonal, a = 13.4 angstrom/b = 13.4 angstrom/c = 9.0 angstrom (space group R3BAR), beta-spodumene, pseudocubic/tetragonal, a = 7.53 angstrom/b = 7.53 angstrom/c = 9.15 angstrom (space group P4(3)2(1)2), beta-eucryptite, monoclinic, a = 7.75 angstrom/b = 5.2 angstrom/c = 11.16 angstrom (space group P6(2)22). The morphology and development of the mineral phases depend on the temperature of formation.