An unbreakable block is an unobtainable block found on top of other blocks underground. It is indestructible through the use of Tools (such as pickaxes), however it can be destroyed using explosive means. A combined explosion rating of 8 is required to destroy an unbreakable block. It closely resembles glass in appearance, however is roughly 6/8 of its size. They are commonly found in groups of over 4 underground, and can be an issue to players who do not have access to Explosives.