Pure Er:YAG Rough, Erbium Color-Change Garnet Stone:Edge, 12.5×11.8×10.7mm, 5.02g These are faceted stones cut

These are faceted stones cut from Vanadium-doped color change sapphire

and they would also be good for cutting exceptionally large round cuts

This stone has a few bubbles and needles

yielding an amazing and unique gem

It's the hardest gem that can feasibly be cut into a die and it is more brilliant than a diamond

Pure Er:YAG Rough, Erbium Color-Change Garnet Stone:Edge, 12.5×11.8×10.7mm, 5.02g These are faceted stones cutThese are facet rough of erbium doped YAG, a lab grown garnet used in lasers for both medicine and industry. Erbium YAG has a very obvious color change between different light sources. Under sunlight and cool LEDs it's a nice orange, but it shifts easily, changing color between Cool LEDs (orange), Warm LEDs (yellow), CFL (strawberry pink), and OLED (magenta) as well as under fluorescent lighting and OLED illumination. Sunlight shows an orangeish pink.