Phase Relationships in the Join Ca(OH)2-CaCO3-Ca3(PO4)2-H2O at 1000 Bars

G. M. Biggar
Grant Institute of Geology, University of Edinburgh

Summary: Phase equilibria involving calcite, apatite, portlandite, liquid, and vapour were determined at 1000 bars. Calcite, apatite, and portlandite melt at 654 °C to form a liquid of composition (wt %), Ca(OH)2 53 %, CaCO3 46 %, Ca3(PO4)2 1 %. With water present melting occurs at 635 °C to form a similar liquid with a low water content. The X-ray diffraction patterns of the equilibrium apatites were not significantly different from synthetic hydroxyapatite.

Mineralogical Magazine; March 1969 v. 37; no. 285; p. 75-82; DOI: 10.1180/minmag.1969.037.285.08
© 1969, The Mineralogical Society
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