Power Pickaxe is a Equip Spell Card.
Spell Cards are usually activated from the hand on your turn unless their type gives another timing window.
On the current TCG and OCG Forbidden & Limited lists tracked here, Power Pickaxe is Unlimited.
YGOPRODeck lists Power Pickaxe for these formats: Duel Links, Edison, TCG, OCG, Master Duel.
A listed print of Power Pickaxe appears in Absolute Powerforce (ABPF-EN053) at Rare rarity.
Among markets shown on this page, the lowest listed snapshot for Power Pickaxe is about $0.25 on Amazon (prices change frequently).
