Transmute

Changes one thing into another. Throw an item on the circle and a ritual runs after a short wait: cobblestone into gravel and gravel into sand, copper into iron, iron into gold, dead coral back to life, and more. The mana is paid a batch at a time, and a stack costs per item but takes no longer. If you cannot afford a batch the ritual pauses and the item waits.

Each change needs a minimum level of the circle: cobblestone into gravel works at level 1, while coal into diamond needs level 8. Higher levels cost more mana.