It looks like a standard hardware store aluminum oxide oil stone. As for oil or water, unless it came pre-saturated in oil, you can use water or oil for lubrication. Once the stone is oiled, it will be an oil only stone from then on. I use a 1:3 mix of mineral oil and kerosene with my oil stones-although any light-medium weight oil should work fine. One thing I've noticed is that keeping oil stones completely drenched in oil really speeds up cutting time.
I think you'll find it a useful stone for setting the bevel on kitchen knives, plane blades, and chisels, but I agree with the others that it is too course for a razor unless you need to remove a nick.
If you need to sharpen a razor on a budget, you might try 1-4-8k SiC sandpaper or lapping film followed by your 12k chinese hone.