NOVELTY - Apparatus (A1) (200) for high pressure crystal or material processing comprises cylindrical capsule region having first and second region, and length defined between regions; annular heating member (240) overlying portion of length; release sleeve (250) disposed between capsule (100) region and heating member configured to dissolved or etched under process conditions without producing dissolution; annular ceramic member (230) disposed around heating member having compressive strength greater than or equal to 0.5 GPa and thermal conductivity less than or equal to 4 watts per meter-Kelvin; and high strength enclosure (210) material.    USE - For high pressure crystal or material processing; and for crystal growth (claimed) such as gallium nitride, aluminium nitride, indium nitride, indium gallium nitride (InGaN), aluminium gallium nitride (AlGaN) and aluminium indium gallium nitride (AlInGaN) used in optoelectronic devices, lasers, light emitting diodes, solar cells, photoelectrochemical water splitting and hydrogen generation, photodetectors, integrated circuits and transistors.    ADVANTAGE - The apparatus is scalable up to very large volumes, and enables cost-effective crystal growth and materials processing under extreme pressure and temperature conditions; facilitates the removal of capsule without damaging the heater, capsule or other elements; and prevents any rupture of a capsule and/or high strength enclosure.    DETAILED DESCRIPTION - Apparatus (200) for high pressure crystal or material processing comprises cylindrical capsule region comprising first and second region, and length defined between regions; annular heating member (240) overlying the portion of length; release sleeve (250) disposed between capsule (100) region and heating member configured to dissolved and/or etched in water, base, acid or organic solvent under at least one process conditions without producing dissolution and/or etching; annular ceramic member (230) having predetermined thickness disposed continuously around perimeter of the heating member of material having compressive strength greater than or equal to 0.5 GPa and thermal conductivity less than or equal to 4 watts per meter-Kelvin; and high strength enclosure (210) material disposed overlying the ceramic member to form high strength enclosure. An INDEPENDENT CLAIM is included for method of crystal growth involving providing apparatus (A1) for high pressure crystal or material processing; and processing capsule with thermal energy greater than 200 degrees C within the capsule to cause the solvent to be superheated.    DESCRIPTION OF DRAWING(S) - The figure shows diagram of a high pressure apparatus.    Capsule (100)    Apparatus (200)    High strength enclosure (210)    Annular ceramic member (230)    Annular heating member (240)    Release sleeve (250)