To excavate ores, you will need to use either TNT, shovels, pickaxes or dynamite in the Mine (starting at level 24)! With these explosives and tools, you will collect different kinds of ores that can be used in the Smelter to make gold, silver, platinum, iron or refined coal bars.
If you’re lucky, some diamonds may also be found. Also remember to check the newspaper ads and your friends shops: they may have ore and bars for you to purchase!