rough grey diamond

Hi, I have a rough grey colored diamond ,I hope if someone have an idea of price/carat.

Please upload images of the rough grey diamond and give more details such as the carat weight of the stone, the mine-of-origin, country-of-origin, a description of the rough stone, any document certifying that the grey stone is a diamond etc. that may be helpful in evaluating the price of the stone.

Hi,it’s 408 Cts.

No documents actually for this stone.