You can make crystal tools using the same recipe model as standard tools. They have a slightly higher durability than irontools but less than diamond. What makes this mod even better is you can also make tools using bones as the handle. This will double the durability regular crystal tools have.
The crystals also make blue glassblocks when you smelt them. They have the same blast resistance as stone so you’ll have a much safer time adoring your walls with these than typical glassblocks.