Certain preserved dragon scales can take on magical properties, either naturally on their own or with the help of a skilled artificer or enchanter. These whetstones are made of such a scale and appear almost gem-like in appearance.

You can use a dragonscale whetstone over the course of 1 minute to sharpen a bladed weapon (such as a longsword, battleaxe, or spear), granting it a +1d4 bonus damage as shown on the table below. The bonuses remain for 1 hour and depend on the whetstone's rarity and the kind of dragon it originally came from. 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.

Dragon: Bonus Damage Type
Black: Acid
Blue: Lightning
Brass: Fire
Bronze: Lightning
Copper: Acid
Gold: Fire
Green: Poison
Red: Fire
Silver: Cold
White: Cold