Ordering of divalent cations in the apatite structure: crystal structure refinements of natural Mn- and Sr-bearing apatite

Abstract

High precision (R ≤ 0.021) single-crystal structure refinements of four apatite samples were undertaken to elucidate the ordering of Mn and Sr in natural apatite and to determine the structural response to substitution of these divalent ions in the apatite atomic arrangement. The crystals studied were naturally occurring and had compositions (Mn1.21, Mn0.42, Sr0.63, and Sr0.29 atoms/ten Ca sites) typical of apatite in many igneous, metamorphic, and sedimentary rocks. -from Authors