Blue Dragonscale Whetstone

You can use a dragonscale whetstone over the course of 1 minute to sharpen a bladed weapon, granting the weapon +2d4 Ice damage for 1 hour. These bonuses are in addition to any other bonuses
a weapon may have.

A whetstone has 5 uses. When you use the last use,
it loses its gem-like shine and becomes a nonmagical scale.