Fuel Gems are required to power the automated mining process and come in various colors.
Fuel Gems may be placed in the players small backpack pocket for easier transportation.
Fuel Gems can be re-sold to the store, with the price depending on the remaining energy in the gem.
The resell price is calculated by the purchasing price of the gem multiplied by the percent of energy remaining, rounded down.
The lowest that a gem can sell for is 1 Rusty Coin.
Once a Fuel Gem is empty, the player can replace it by grabbing it from the panel and replacing it with a new gem.
The horizontal light beams above each Fuel Gem in the panel represents the remaining energy in the gem. A brighter beam means more remaining energy, whereas a beam that is turned off represents an empty gem.
The base duration is calculated at Fuel Gem Extractor level 5.
Cost: 2 Rusty Coins
Base Duration: 5 Minutes
Cost per Minute: 0.4 Rusty Coins
Cost: 35 Rusty Coins
Base Duration: 40 Minutes
Cost per Minute: 0.875 Rusty Coins
Cost: 12 Copper Coins
Base Duration: 200 Minutes
Cost per Minute: 0.6 Rusty Coins