Which statement describes Photoluminescence Mapping?

• A. A spectroscopy technique that collects PL data across the entire surface of a diamond, showing subtle distinctions in defect concentrations.
• B. A method to map the refractive index across a gem.
• C. A way to measure fluorescence under UV light.
• D. A technique to photograph a diamond under polarized light.

Answer: (A)

Photoluminescence mapping is a spectroscopy approach that excites a diamond with light and records the emitted luminescence across the stone’s surface to build a spatial map of defect-related emissions. By scanning points across the surface, it creates an image where brightness or color reflects the concentration and distribution of specific color centers or defects. This spatial insight helps reveal subtle variations in defect concentrations that bulk measurements might miss, such as growth zoning or treatment effects.

So, the statement that describes photoluminescence mapping is the one that says it collects PL data across the entire surface of a diamond, showing subtle distinctions in defect concentrations. The other options refer to different techniques—mapping refractive index, measuring fluorescence in a single area, or photographing under polarized light—which are distinct from PL mapping.