What is this stone?

... @Marote .....looks like your glass..... eh?

Indeed.
What type of black lite was it? 365nm or 395nm?

there are types ???

yup

If the glass turned green with 365nm, it can be uranium or manganese glass.
If the glass turned green with 395nm, it can be uranium glass.
As it's a faint green, I would guess a 365nm light was used, and that it's manganese, as uranium glass usually is much brighter.

@Marote.......

well , maybe the gal will come back , and we'll figure it out..