The Crystal Axe is the third strongest axe in the game.
It can be crafted when the player achieves Level 50.
How to Obtain
All you have to do is collect Crystal and smelt some Gold. Then you will have enough to get this. The suggested way to get Crystal is to wait for the Meteor (Crystal ones are fairly common) and mine the Shellies (If you can) and the Meteor Rocks. If you want even more Crystal then you can also get more from the Meteor Core.
The Crystal Axe is actually not very necessary for high-tier players as you would rarely need to collect wood. It is better to obtain wood from Rafts that are about. Raft: Low Hp - 2 Logs and then Tree: 40hp - 2 Logs and 1 Leaf.