Contribution

The structural property of synthetic gehlenite, Ca2Al2SiO7

Kimata, M.; Ii, N. Ibaraki

Abstract

The crystal structure of synthetic gehlenite, Ca2Al2SiO7, was refined to 2.4 % through three dimensional analysis of single-crystal X-ray diffraction data. In this gehlenite there is the same partial ordering with Al in T(1) tetra-hedra and Al1/2Si1/2 in T(2) one as in natural gehlenite, but both the former cell parameters and structural property are slightly different from the latter. The existence of melilite solid solution between gehlenite and akermanite admits the interpretation that structural property of this synthetic gehlenite is more suitable for the gehlenite as an end-member. In a tetrahedron of melilite, moreover, pure Al-O distance was derived as 1.749 Ä from the geometrical and electrostatic calculation.

Mots-clefs

Gehlenite • refinement • cell dimensions • order-disorder • silicon • aluminium • tetrahedra • distortion • melilite • solid solution