The mining system aims to reward the player with coins with his well-earned efforts in the caves.
You can find the caves in the build area, you can usually type !go cave, !go mine, !go volcano in the chat to teleport directly into the area.
Alternatively if you're in the build area look for this building:

The basics of the mining system are very simple. Glowing rocks will spawn in the caves, hit them with your crowback or pickaxe to get ores.
A pickaxe will be given to you as soon as you enter the area, use it as its more effective to mine ores with it!
Copper:

Silver:

Gold:

Once you have mined these rocks, your HUD will show you how much you have of each.
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When you get ores, you can do two things with them:
mining pointscoinsOnce you have acquired ores you will want to find the Miner NPC, which can be found there:

After talking to the Miner, a menu will prompt:

mining points you will get from each of your ores on the leftClick the Turn in for Coins button to exchange your collected ores for coins. You can also exchange your ores for mining points.
Mining points are used to upgrade your crowbar stats, like your Hit Speed, Range or Bonus Ore Chance. These stats go up to level 50 and allow you to be much more efficient in your efforts to collect more ores.
To get points click Turn in for Points to exchange your ores against points. You can then use them right away on the Pickaxe Uprades on the right of the miner menu.

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