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.
Under UV illumination this phenomenon is even more striking, with the stone emitting a very strong apple-green fluorescence in both long-wave (image 4) and short-wave illumination (image 5).

Despite its visual impact, very few faceted are produced, with this one being a well-cut example.

weight:  2.55 carats
shape:   Rectangular baguette cut with opposed bar crown facets
dimensions:   9.19 x 3.99 x 3.80 mm
treatment:  Not applicable