Ice
From The Blockheads Wiki
Ice is a block created when it gets cold and snows on water. It is recommended to mine ice with a pickaxe for best results. Your Blockhead is able to run across ice making it possible to cross oceans without a boat. If you sleep on ice an it melts a Blockhead will immediately wake up.
Ice does not melt while carried in a Blockhead's Inventory or stored in a container.
Uses
While ice can be used for construction, its tendency to melt under warm conditions makes it impractical except under arctic conditions. It has no known use in crafting.
Ice can be used to transport water without using a bucket.