F. Tutti et al., High pressure phase transformation of jadeite and stability of NaAlSiO4 with calcium-ferrite type structure in the lower mantle conditions, GEOPHYS R L, 27(14), 2000, pp. 2025-2028
Phase transformation of jadeite clinopyroxene was studied at temperatures o
f 800 and 2200 degrees C at pressures between 30-75 GPa in externally elect
rically heated and internally laser-heated diamond anvil cells. It has been
found that jadeite transforms to the assemblage of NaAlSiO4 (calcium-ferri
te type structure) plus stishovite at high pressure and temperatures. There
fore NaAlSiO4 calcium-ferrite is stable at the deep lower mantle pressure a
nd temperature conditions.