At which ultraviolet wavelength do all diamonds show fluorescence?

At which ultraviolet wavelength do all diamonds show fluorescence?

• A. All diamonds show fluorescence at ultra-shortwave UV.
• B. All diamonds show fluorescence at shortwave UV.
• C. No diamonds fluoresce under UV.
• D. Only colored diamonds fluoresce under UV.

Answer: (A)

Ultraviolet fluorescence in diamonds comes from photons exciting defects or impurities in the crystal, which then emit visible light as they return to the ground state. Ultra-shortwave UV carries very high-energy photons, and this energy is sufficient to trigger fluorescence across a wide range of diamonds regardless of their color or specific impurity content. That universal response under ultra-shortwave UV is why this option is considered the best answer. Under other UV ranges, fluorescence can vary a lot: some diamonds may fluoresce, others weakly or not at all, and colorless stones can fluoresce just as blue-fluorescence-prone stones do, but not universally.

Ultraviolet fluorescence in diamonds comes from photons exciting defects or impurities in the crystal, which then emit visible light as they return to the ground state. Ultra-shortwave UV carries very high-energy photons, and this energy is sufficient to trigger fluorescence across a wide range of diamonds regardless of their color or specific impurity content. That universal response under ultra-shortwave UV is why this option is considered the best answer. Under other UV ranges, fluorescence can vary a lot: some diamonds may fluoresce, others weakly or not at all, and colorless stones can fluoresce just as blue-fluorescence-prone stones do, but not universally.