Orange Diamond with Unusual Color Origin
This 1.53 ct heart-shaped diamond (6.84 × 7.76 × 3.88 mm) was color graded as Fancy Intense pinkish orange (figure 1). Color was distributed evenly throughout the stone, which was very clean and showed no internal features under the microscope. The absorption spectrum in the infrared region revealed that it was a regular type IIa diamond, with no nitrogen-or hydrogen-related absorptions. The UV-Vis region showed a broad absorption band centered at ~550 nm and its corresponding band at ~390 nm, absorption features typical of natural type IIa pink diamonds. From the optical centers detected, we would not expect this diamond to show a dominant orange bodycolor.
The reason for this discrepancy is not fully understood. Our finding from this stone demonstrates the complexity of diamond color origin.