.... B-type CO 3 means CO 3 which occupies the tetrahedral anion site in the apatite structure. Plots of CO 3 -bearing apatite and ellestadite, whose B-type CO 3 is controlled mainly by the substitution mechanism (SO 4 ,CO 3 ) 2–  + (SiO 4 ) 4–  = 2(PO 4 ) 3– , from the literature are also shown. Data...

... analysis of eighteen specimens of different phosphorus contents proves that the Si:S ratio is essentially 1:1 and yields the idealized general formula Ca 10 (SiO 4 ) 3−x (SO 4 ) 3−x (PO 4 ) 2X (OH,F,Cl) 2 , where x = 0 to 3. The members of this series for which x = 0 and 3/2 have been labelled “ellestadite...

... into five groups, based on crystal-chemical arguments: apatite group, hedyphane group, belovite group, britholite group, and ellestadite group. The abundance of distinct ions which may be hosted at the key-sites [M = Ca 2+ , Pb 2+ , Ba 2+ , Sr 2+ , Mn 2+ , Na + , Ce 3+ , La 3+ , Y 3+ , Bi 3+ ; T = P 5...

... (or tilleyite, afwillite, kilchoanite) and, at a later stage, a granditic garnet, and (2) the complete transformation of gehlenite to vesuvianite, associated with minor clintonite (+ monticellite and probably ellestadite), usually along a sharp front typically rimmed by a 0.5-mm-wide zone of Al-rich gehlenite...