Description
Numerous glassy, spherical and reniform clusters of Hyalite (Opal-AN) cover most of the basaltic matrix of this specimen. The clusters are colorless translucent to transparent but explode into a neon green firework when exposed to short wave UV light. A very aesthetic specimen from Valeč (Waltsch), a famous locality for Hyalite (Opal-AN) that has been exploited since the 19th century, and specimens from this locality grace many museum collections of the world.