HELP How to get rough diamond clean?

[know1ukn014]

HELP" I have rough diamonds from different places, and have used so many different things trying to clean a couple that were in a forest fire, and I found after a landslide, and I originally was looking for gold. They have a black crust. They are not black diamonds, as I did get a much smaller one clean, but it took me 4 yrs. of using wire brushes and everything know to man.It has passed every diamond test. I have done quite a bit of research about the are, which was a great sea thousands of yrs. ago, and then a river, now a desert that the unusually high winds have blown the top soil away. There was a find in Canada and the ones they found looked like this, but they crushed them, and it would be nice to keep this size. I had a tiny one anaiyzed for chemical content and it passed that test also, I have a large round one, and do not have another 4 yrs., so if anyone has any ideas, other than a crusher, I sure would appreciate it.
Thank you in advance.

 

[SirGuy]

Do you have any photos you can share? That would help folks get a better idea of what you're talking about.