Hackmanite is a sulfur bearing variety of Sodalite famous for its tenebrescence. It is a rare mineral only found in a few locales of the world. Our rough is sourced from the legendary gem city of Mogok, Myanmar.
Tenebrescence is the ability of a mineral to change color when exposed to light, in this case a UV light. The phenomena will reverse itself after a few minutes to a few hours and can be repeated again and again.