Sage's Stone is a Normal 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, Sage's Stone is Unlimited.
YGOPRODeck lists Sage's Stone for these formats: GOAT, Speed Duel, OCG GOAT, Duel Links, Common Charity, Edison, TCG, OCG, Master Duel.
Sage's Stone belongs to the Dark Magician archetype—use that tag when searching for engine pieces and tech options.
A listed print of Sage's Stone appears in Gold Series 4: Pyramids Edition (GLD4-EN038) at Common rarity.
Among markets shown on this page, the lowest listed snapshot for Sage's Stone is about $1.96 on Cardmarket (prices change frequently).
