Symmetry of platelet defects in diamond: new insights with synchrotron light

Acta Cryst. (2010). B66, 493-496 (doi.org/10.1107/S0108768110031071)

Nearly 98% of natural diamonds are of type Ia. They contain up to 0.3% nitrogen, mainly associated with planar defects, called platelets. As all the platelets are coherently integrated into the single-crystal diamond matrix, their assembly can be treated as a twinned composite crystal. Three-dimensional mapping of rod-like diffuse scattering from Ia diamonds allowed us to identify the periodicity (√8a₀ × √1/2a₀ × −0.55a₀) and some symmetry elements of the platelets. Our findings should guide further work to solve the structure of these defects.