Vintage large GALENA Crystal Radio vintage part ~~

Description

I was going through the drawers of an old radio shop, and found some old grid leak items ( which I listed) and then came across this rock.  use zoom, I believe it to be a Galena crystal for crystal radios.  please use zoom.  it clicked in my mind it would make sense, that being said please use zoom, this is a final sale.
I always welcome emails as I always can learn, if you know more about this, please email me.   thanks
final sale as found. untested , thanks