Consider this Part 2 from What happens to objects, changed while transmuted using Minor Alchemy, after they revert?
This is regarding the School of Transmutation wizard's Minor Alchemy feature (PHB, p. 119):
Starting at 2nd level when you select this school, you can temporarily alter the physical properties of one nonmagical object, changing it from one substance into another. You perform a special alchemical procedure on one object composed entirely of wood, stone (but not a gemstone), iron, copper, or silver, transforming it into a different one of those materials. For each 10 minutes you spend performing the procedure, you can transform up to 1 cubic foot of material. After 1 hour, or until you lose your concentration (as if you were concentrating on a spell), the material reverts to its original substance.
Specifically, with spells like Mold Earth (can manipulate stone/earth, changes last 1 hour), or Meld Into Stone (put body and belongings into stasis within a "coffin" of stone), what happens when the stone that you're working with was transmuted from wood and reverts back?
In addition, Fabricate states that the quality of the finished product depends on the material used, but does transmuting cheap wood to silver mean that I end up with a high quality silver product followed by it reverting to a high-quality wood product?
I guess, to simplify this question, assuming I'm converting wood into stone via Minor Alchemy: When I cast a spell that requires stone, does my spell:
- Fail immediately (as I'm not using a proper material)
- If this is true (I can't turn wood to stone, because it's not real stone), could I turn stone to wood and treat it as a stone material?
- Fail the moment Minor Alchemy ceases (as I'm no longer using stone)
- Continue to attempt the magic on the reverted material as normal (like with Mold Earth, magically ending up with colored, shape-shifted wood for the next hour)
- Some other event
Best Answer
The answer is going to depend on whether the spell is still in effect when the reversion happens.
Fabricate
Fabricate is instantaneous. You cast the spell, the magic shapes the material, and then it holds that shape forever just as if you'd cast it or carved it.
The result of transmuting some cheap wood to fine silver, then Fabricating it into high-quality jewelry, then having it revert back, is that you now have fine jewelry made out of cheap wood. The delicate shapes are not going to hold up to wear. It's going to have the grain structure of the wood, which may be too coarse to show the details you want. It may have material flaws like knots and pockets of sap.
Fabricate has the limitation that making high-quality goods requires crafting proficiency appropriate to the thing you're making. I'd say that in this case, if you're proficient with both jeweler's and woodworker's tools, and knew that the silver was going to revert to wood, you could end up with high-quality woodcrafts. Otherwise you're going to get junk.
Meld Into Stone
This has a duration of 8 hours. It also addresses this issue:
So, good luck with that.
Mold Earth is instantaneous--kind of, sometimes.
The basic use of Mold Earth is like a magical shovel: it takes a chunk of dirt or stone and moves it.
But it also has those persistent effects that last 1 hour. My initial reading was that the spell reshapes the soil to achieve those effects, instantaneously, and then they disintegrate after an hour as the soil returns to its natural state, like a sandcastle. But you can dismiss the effect, which implies that the magic is still doing something. I could see a DM ruling either way on this.