I would say yes. Traditionally, glass is used but I am sure what you suggest would be OK.
johnep

 

ANY stable, flat furface can be used.

George

 

There was a post on the forum a few days ago where a person purchased a marble tile for sharpening, then got home and found it was not flat.

If the granite tile is flat, then you could use this, or any other flat/rigid surface. Best to check that it is flat before you sharpen a blade to match a curved tile.

 

I have marble tile and mine is flat...or at least as flat as anything that I have to check that it is flat.... I have laid a square across it on the face along all four sides, down the middle, and diagonally.

 

I used to use a table saw top salvaged from a parted out cast iron craftsman, but I found a flat granite piece that I now use. It works well. Its some kind of sink cut out from an installed counter top. As stated above, make sure its flat.

 

Call me cheap, but I begged a sink cut-out from a local granite shop. Heavy, flat, and free. Beat that.
Bill

 

I love my diamond hone to rough in chisel and plane blades, then finish with 2 waterstones. Then when the waterstones need flattening, I slap wet/dry paper on the diamond hone (stays flat), and true them up....

 

If your looking for something flat why not use a granet stone used by machinist. They are very flat somewhere around .0005 (1/2 thou). Grizzly sells them very reasonable.