Ice can be easily destroyed without tools, but the use of a pick speeds up the process. The object cannot drop.
Ice can generated naturally in Winter by cryogenic rivers, lakes, or seas.
Ice is slippery, causing entities to slide, including items. This also allows for increased speed in water currents by placing the ice under the water current.
When a non-full object is placed on top of ice, the object has the same "slipperiness" as the ice below it.
Ice can be used to create water: if there is another object directly underneath the ice block, the ice will revert to water when broken. Ice will also melt into water if the temperature is high.