Another fun tip, mine anything you need in-game. If you are not in a hurry, just mine it. Dig Deep maps hold pretty much anything you'd want. Diamonds, Rubies, Sapphires, Carbon, Obsidian, Uranium, Platinum...tons of wonderfully expensive ores and minerals. Ya just gotta go searching for them. Each one is usually in abundance at a certain layer, the only thing you have to do is use your mini-map to search for the "buried treasure." And, the best part of all: THEY ARE FREE! We can break down which layers generally hold which of these, and more if anyone wants. I know a few, and other Dig Deep pros know most of the rest!