Figure 4. Under polarized light, the Fancy Vivid yellowish green synthetic diamond (left) displays patchy yellow color zoning caused by isolated nitrogen and a green color concentration on the culet caused by post-growth artificial irradiation treatment. The Fancy red sample (right) shows yellow to near-colorless zones following the cubic growth sectors, with the red color caused by post-growth annealing. Photomicrographs by Yixin (Jessie) Zhou; fields of view 7.19 mm (left) and 4.79 mm (right).
more: Treatment Process