An unusual and uncommon lab-created gem material, this electric coloured yellow-green gemstone is a Cerium-doped Lutetium Aluminium Garnet.

Originally created using the HDSM method for its light-emitting properties and used in the optical industry as a scintillator, this material has plenty to commend its use as a gem material.

Its striking colour seems almost fluorescent even in standard household lighting and is truly remarkable when viewed in natural sunlight.
Under UV illumination this is confirmed in spades, with the stone emitting a very strong apple-green fluorescence in both long- and short-wave illumination (images 4 and 5).

Despite its visual impact, very few faceted are produced, with this one being a well-cut example.
It is flaw-free and very well cut, with a lively appearance.

weight:  5.72 carats
shape:   Multifaceted rectangular baguette cut
dimensions:   10.80 x 5.49 x 4.86 mm
treatment:  Not applicable