Willemite Ore is a mineral (zinc silicate) that glows bright green under black light and a few will phosphorescence. This rare mineral, a source of zinc ore, is one of the finest specimens of fluorescent material.
When I received this blank from the folks at Diamond Cast in my monthly subscription box, I knew it'd make an awesome pen. Paired with a black oxide clip on purpose so it wouldn't take away form the beauty of the blank. Once again, pictures do not do it justice.. I'm a pen maker, not a photographer :)
The pen is fully postable.