Gemological Characteristic Difference between Colorless CVD Synthetic Diamonds and Natural Diamonds.
Level 5 - mechanism / opinion, no new human data
Benchtop materials characterization study with no human data.
PubMed 34683817 · doi:10.3390/ma14206225
What was done
Researchers compared the gemological, spectroscopic, and luminescent properties of colorless chemical vapor deposition (CVD) synthetic diamonds produced by a Chinese manufacturer against natural colorless diamonds.
What was found
The abstract does not provide exact quantitative metrics or sample counts. Compared to natural diamonds, CVD synthetic diamonds exhibited high-order interference colors, more pronounced abnormal birefringence, and lamellar growth structures (compared to irregular ring-like growth structures in natural diamonds). Infrared spectroscopy classified all CVD samples as Type IIa and natural samples as Type Ia. CVD samples displayed mottled luminescence patterns with blue, orange-red, purple-red, and blue fluorescence, whereas most natural samples showed blue fluorescence.
Why it matters
It defines diagnostic criteria—particularly growth structure, luminescence, and infrared classification—necessary to reliably distinguish lab-grown CVD diamonds from natural diamonds in gemological testing.
Limits
The abstract does not state the sample size (n) tested or provide quantitative statistical metrics. Only CVD diamonds from a single manufacturer were evaluated, which may limit generalizability across different synthesis methods or producers.