Stone

Stone is pretty much the same thing as rock, although some games, notably Crawl distinguish them.

A stone is also a unit of mass measurement in the Imperial system, equivalent to 14 pounds or 6.35 kilogrammes. Some games have used the stone in this meaning, notably ADOM, where the stone was the only measurement unit to express item mass (interestingly, the PC’s body mass could be expressed either in pounds or kilogrammes, according to the game’s configuration). As Thomas Biskup stated, a stone in ADOM is equivalent to 50 grammes.