High-Temperature Solution Growth of Chlorspodiosite and Chlorapatite Crystals

Abstract

Well-formed crystals of chlorspodiosite [Ca₂ClPO₄] and chlorapatite [Ca₅Cl(PO₄)3] were grown in the Ca₂ClPO₄-CaCl₂ high-temperature solutions. Phase diagram of Ca₂CllPO₄-CaCl₂was investigated on the basis of the solubility and quenching data. Crystal growth of Ca₂ClPO₄was conducted by heating mixtures containing 5 mol% Ca₂ClPO₄ at 900, 1000, or 1100° C for 10 h, followed by cooling to 600 ° C at a rate of 5 ° C Grown Ca₂ClPO₄ crystals were up to 9 mm in size, colorless, and transparent. The crystals had the forms of rod and plate. The forms were dependent on the soak temperature. Regarding of crystal form, the grown crystals were bounded by {001}, {100}, and {110} faces. On the other hand, crystal growth of Ca₅Cl(PO₄)₃ was conducted by heating mixtures containing 15 mol% Ca₂ClPO₄ at 1200 ° C for 10 h, followed by cooling to 1050 ° C at a rate of 5 ° C 11-1 and quenching from 1050 ° C to room temperature. Grown Ca5C1(PO4)3 crystals were up to 5_mm in size, colorless, and transparent. The crystals had the form of hexagonal prism {1010} with pyramidal end faces {10i1}.