Aqua Scepter

The Aqua Scepter is a staff-type weapon received from Chests inside Dungeons. It shoots a stream of water 7 blocks from the player with a damage of 15 and consumes 12 mana in the process. Although its speed is slow, when the attack button is held it shoots a continuous stream of water and constantly consumes mana.

It has been confirmed by the developer that you will be able to use this on Lava to generate Obsidian in a later patch.