Sapphire D20 53ct, 1980s Infrared Countermeasures Sapphire T-shirts but there are more to

but there are more to come

scintillator-grade cerium YAG look dim

LuAG is an exotic lab-created crystal with the same structure as natural garnets

dual-doped neodymium+chromium YAG

These can of course be faceted as gems and are just extremely cool

Sapphire D20 53ct, 1980s Infrared Countermeasures Sapphire T-shirts but there are more toThis is a D20 I faceted from white sapphire. It weighs in at 53 carats and measures 20mm point to point. The numbering is not perfect the center of the '4' on 14 ended up filled in. I faceted this d20 from a sapphire rod which was intended to go into infrared countermeasures against heatseeking missiles (IRCM) back in the cold war so not only is it bright and durable it gets a +2 in saving throws against fire!