If I had a piece that large I would keep it as a specimen piece.
Maybe a museum would be interested in it. Colorado's gem stone is
the Aquamarine which is Beryl. Check with the country or local area
museums from the area which the piece came from.
I have my eye on a piece that is still in the matrix rock that is
about 4 inches in diameter, but I will have a lot of work to get it
Good luck with your piece,