Jadeite, NaAlSi2O6 is an important mineral in metamorphic rocks and occurs in low as well as high metamorphic grade. Previously we have determined the thermoelastic properties at low temperatures which are consistent with both heat capacity measurements and vibrational spectroscopy. As part of this work we have developed a model to determine the structural basis for thermal and pressure induced changes. High temperature thermoelastic properties have been determined using EDXRD which we argue are of poor quality and are potentially unreliable. We propose to study jadeite using the HT-HP cell to determine the structural response to pressure and temperature but also to derive more reliable values for the thermoelastic properties.