Artificers Whetstone

This strange black grooved whetstone seems to almost vibrate in ones hand when holding it. During a short rest you may take the time to sharpen a weapon or up to 20 pieces of ammunition. Doing so imparts some of the honing enchantment into the blade or ammunition infusing the following temporary benefits for 1d4-1 hours

• The weapon or Ammunition is considered magical 
• When ever you attack with a melee weapon and roll a Natural 20 or critical hit your weapon does an additional 1d6 damage of the weapons type
• If it is a ranged weapon attack using ammunition and roll a Natural 20 or critical hit, the weapon cuts deeper than normal causing them to bleed profusely dealing an additional 1d4 damage at the start of their next turn for 1 turn  

Once you use this whetstone roll a d20 on a 1 the stone crumbles to dust in your hands.