A crushed gem is an accidental product that is occasionally made when using a chisel on an uncut semiprecious gem (opal, jade and red topaz). Players gain a small amount of Crafting experience when a gem is crushed in this way.
This item is of very limited use, with the only application coming from the Fairytale I - Growing Pains quest to make the magic secateurs. Players can sell crushed gems to the general store in Shilo Village for 1 coin each, however, most people just drop them in favour of using the inventory space for gems.
The item is also tradeable but cannot be sold on the Grand Exchange.