Faceted Zinc Sphalerite, White ZnS Gemstones Stone:Round (Crackled), 6mm, avg. 0.9ct and occasional blue

and occasional blue

a crystal grown for its insanely strong fluorescence

but it is never available in large sizes

Though the gem world sometimes thinks of it only as a diamond stand-in I prefer to think of it as a gem all its own

Faceted Zinc Sphalerite, White ZnS Gemstones Stone:Round (Crackled), 6mm, avg. 0.9ct and occasional blueThese are faceted labmade Zinc Sphalerite (ZnS). While facet grade sphalerite is only rarely found in nature (and usually has a dark red or orange color), and is very difficult to cut, if you're brave enough to cut it, the resulting stones have incredible fire and dispersion. Colorless ZnS is grown for use for optics, and various doped versions are used as phosphors if you have an old oscilloscope, the iconic blue or green display panel likely used