From Dark and Darker Wiki
Ores
Ores can be extracted from ore Deposits located throughout the various maps. Ore Deposits can be mined by equipping a Pickaxe from your quickslots. It will take you multiple cycles of mining until you're able to break them to harvest the ores.
There are 2 types of ores at the moment, Cobalt, and Rubysilver.
Cobalts creates gear has up to 3 enchantments. Rubysilver crafted gear has up to 4 enchantments.
Ores can then be converted via the Services option to either Powder at the Alchemist or Ingot at the Weaponsmith. Crafting these will cost 6 and 10 Ores respectively.
After you have a sufficient amount of materials, you will be able to craft the armor of your choice. (Currently there is no option to craft any weapons with this ore.)
Cobalt
Cobalt ores can be found in Goblin Cave.
Cobalt Ingot is used in Heavy Armor and Cobalt Powder is used in Leather and Light Armor crafts.
Rubysilver
Rubysilver ores can be found in Crypt and Goblin Cave.
Rubysilver Ingot is used in Heavy Armor and Rubysilver Powder is used in Leather and Light Armor crafts.
Tips
Hitting deposits with multiple people will not affect the time it takes for nodes to break and only one person will receive 4-5 Rubysilver Ores.
Your character will be extremely vulnerable during this process, so it is best to get to cover and clear the rooms before attempting to mine.