Mineraccoon (Level 1): Take a purple Crystal with a cost of 1 from the Mine. This action does not count as mining, therefore it does not interact with other skills or Artifacts that affect the Mine action.
Diggerhino (Level 2): Change the color of one Crystal in the Mine to a different color of your choice for the duration of your turn. The cost to Mine that Crystal this turn is also reduced by 1. If this reduces the cost to 0, you must still perform the Mine action, even though you do not use a card to pay for it.
Ancientone (Level 3): This turn, you pay 4 less for Artifacts when you Collect them. These savings are cumulative with any other card which also gives you a discount. For example, if your Leader is an Ancientone, and you play another Ancientone as your first action, you can Collect an Artifact with your second Action and pay 8 less. If the cost of an Artifact is reduced to 0 or less, you must still perform the Collect action, even though you do not use a card to pay for it.
Maccarat (Level 4): This turn, the mining cost of all Crystals is reduced by 4. Consequently, you can Mine a Crystal with a mining cost of 1 or 3 without spending a card, but you must still perform the Mine action.