gems, luminescence, titanate, beryl, pezzotaite, tourmaline, synthetic opal, lead glass, hydrozincite, dumortierite

This article reviews blue shortwave-excited luminescence (BSL) in natural and synthetic materials, focusing on seven minerals and gems—such as beryl (morganite), dumortierite, hydrozincite, pezzotaite, and elbaite—as well as three reference materials where BSL is linked to titanate groups (TiO₆): benitoite, Ti-doped synthetic sapphire, and spinel. Under 254 nm excitation, these materials exhibit broad blue emission centered at 420–480 nm, with excitation spectra peaking at 230–290 nm and luminescence decay times around 20 μs. The study proposes that this BSL is due to TiO₆ groups present at concentrations ≥20 ppmw, with no other known luminescence activators matching this behavior.