Silver cuff with 3" turquoise - what value might it have?

I bought this cuff in Denver about 10 years ago, already with age. Any idea on where the turquoise might be from? It’s value? No hallmark, just a sterling stamp.

The stone looks huge. It is always difficult from a picture to get an idea of what the size and weight of a stone would be. However, just from what you have provided I would guess the stone to be somewhere around 1000 carats. Turquoise keeps getting more and more expensive. I would start with .65 cents a carat. Just saw a 800 plus carat piece of Royston that was a better grade than this at 1.35 a carat. Thanks for sharing.

This is an amazing piece!!!