Mithril Drill

Mithril Drill60 GRAM in game (≈6,000 CROWN at the presale rate), 30 GRAM in the presale

Adds +50 mining power. The power of every drill you own adds up, so a new drill does not replace the old one, it stacks on top.

Shards per hour from this drill = 50 × 300 × buildings × boosts × depth

At current competition that is about 324.14 CROWN per day, paying back in roughly 18.50 days.