Durability is system that applies to mining tools. When a tool has high durability, it will mine faster than it would when the durability has run out.
Durability decreases only when you mine blocks and will eventually be reset when you travel back to your spaceship. Note that as of Beta v. Indignant Koala, this auto-repair function has not yet been implemented.
To increase a tool's durability, use (by right clicking with it on your tool) an ore to sharpen it. Different ores will replenish different amount of durability.
- Sometimes you have to take the ore and move it to your inventory to sharpen your tool.