Non-Radioactive.
These rare Hackmanite crystals exhibit one of nature's rarest treats, Tenebrescence! The first picture shows the stones after exposure to white light which "resets" them to this color. After exposure to 365nm UV light which shows a fierce UV fluorescence, the stones will remain dark purple indefinitely until being reset again. A fun treat for those who have yet to experience this magical part of the mineral world. 
You get one gram similar to the one pictured above.
Tenebrescent Hackmanite
Badakhshan, Afghanistan