My lastest and greatest rock pile find.

[Suile]

On Monday of this week I argeed to help my new sister in law load and unload her horse trailer with hay from the field
after getting done helping I decided to take a look at the rocks that where laying around.
Man am I glad I picked up this gem off the ground.
It weights in about 2.65 pounds.
I just simply rub my made in China chef knife I use at my job on it dry it makes a wonderfully fine cutting noise of steel.
My Boss rubbed his Mac 8 inch chef knife on it and said wow.
Does any one know what kind of rock it is.
I use it dry cause water can't lube it at all and is nice and clean.