Which of the following is not listed as a technology used to assess rough potential?

• A. Thermal gravimetric analysis
• B. Optical sensing
• C. Infrared spectroscopy
• D. X-ray imaging

Answer: (A)

In rough diamond evaluation, the aim is to quickly and non-destructively gauge factors that affect value after cutting—things like color tendencies, impurity content, and internal structure. Thermal gravimetric analysis involves heating the sample and measuring weight changes, which is a destructive test that reveals volatile content or decomposition behavior rather than anything about the gem’s potential value or how it will cut and yield. That’s why it isn’t used to assess rough potential. The other technologies fit the purpose: optical sensing helps assess color and surface characteristics, infrared spectroscopy identifies specific impurities and defect-related features that influence value, and X-ray imaging reveals internal inclusions and structural details that affect yield and clarity after cutting.