Gray 'Phantom' YAG Garnet Cut Stones

These are lab created light gray laser garnet faceted stones. We call it "Phantom" YAG because it has a phantom purple glow under UV.

The rough was grown by the HDSM method and comes from the 'prow' of the boat-shaped crucibles, at the tip of the crystal that concentrates various impurities.  I don't know what causes this color but it is very unusual. The crystal was apparently grown for use in lasers.