I've stumbled accross an on rock which looks and could be made outta red and black granite and possibly a native grinding stone. Maybe take couple looks and let me know what ya think?!?
Well it looks more like a big piece of flint or chert. It is to hard to see the "Bowl" section by the pics you have provided. That would be the part we need to see. It has a nice shape to it.
Its hard to determine that it is a granite stone or not. There are plenty of stones like this. I don't know whether it is granite or not but I have same colored Granite Countertops Keystone in my kitchen.
Looks like it could be a nice mortar stone, some close ups of the depression area would be interesting to see. Did you take it home with you, or is it still where you found it? Frome the photo it looks like a fine grained quartzite to me?