Unusual Cloud in Diamond
GIA’s laboratories issue clarity grades for many diamonds for the gem trade. So when we observe a diamond with clarity characteristics we have not encountered before, we generally consider those features to be rather rare and worth documenting for future reference.
Recently, just such a diamond was examined in the Carlsbad lab. It was a 0.62 ct round brilliant with very good polish and symmetry and a very light brown bodycolor. The diamond exhibited a faint light blue fluorescence to long-wave radiation and an inert reaction upon exposure to short-wave UV.
The gem’s I1 clarity grade resulted from a delicate cloud of cruciform dislocations (see above), forming numerous small interlinked cross-like patterns in the diamond host, which were visible face-up through the table facet. The shape and orientation of the overall cloud suggests that the cube face of the original diamond crystal was parallel to the table facet of the faceted diamond.
We regularly encounter cloud clarity features in diamonds, but this fascinating geometric network was a “first encounter” for us.
