If you hit a diamond with a hammer, would it break the diamond or dent the hammer?

-Assuming a standard steel hammer like you'd use to drive nails. I know diamonds a very hard, but is that the same thing as 'tough'? As in resistance to shock and impact? Would a better test be to place the gem in a hydraulic press? What kind of pressure range would be necessay to crush a 1 ct diamond vs other hard materials?