For Beta counting and Beta spectroscopy parpuses, Antracene (C14H10) an organic scintillator material is widely used. It’s light output yeld is the highest of the organic scintillator materials family.

I’ve bought a russian crystal that have a removable alluminium cap. Under the cap there is the crystal. It’s front face is alluminized because alluminium act as a screen for Alpha particles. With alluminium cap on it still detects hard Beta’s.

Crystal with it’s removable cap

My crystal is not clear… maybe is damaged?

It’s strong UV fluorescence