Frostshard (3.5e Equipment)
From D&D Wiki
Description: A frostshard is a small piece of ice that does not melt and feels quite cold to the touch. It is anywhere from 3 to 6 inches in length and weighs about 1 lb. When broken, a Frostshard unleashes a blast of ice cold along with small ice fragments that ices anything over that isn't overly hot. Frostshards can be either made, or found in an ice environment such as a glacier.
Use as Weapon: A Frostshard can be thrown at a range of 15 ft. A direct hit deals 1d6 cold damage, and every creature within 5 feet takes 1 cold damage. It also ices over the surface of the target's square, requiring a DC 12 Balance check to avoid falling prone. The ice melts in 5 rounds. A Frostshard deals an extra 1d6 damage to creatures with the Fire subtype.
Other: A Frostshard can also be used in Resist Fire potions to increase the resistance by 2. A Frostshard costs 30gp. The Craft (Alchemy) DC is 22.