Fantasy Cut Optical Sapphire Stones

These are fantasy cut stones out of clear optical sapphire. 

We have two types - an older variety with lower purity grown sometime in the '70s by Union Carbide, and a newer type grown by Rubicon, one of the top US growers of sapphire, and purchased from a factory closing auction.

While both of them are colorless under normal conditions main difference is that Union Carbide material has a faint pink fluorescence under 365 nm UV and a faint blue fluorescence under 222 nm UV, likely due to trace chromium and titanium.  Pretty neat if you have a UV display setup!

The sapphire crystals were intended for use in high end optics, filters, and as a substrate to grow bespoke computer chips. This is a mixture of material that either never got fully processed, or was rejected for optical purposes due to surface chips, veils or maybe minor optical misalignments.