True Alchemy

You draw on the entirety of alchemical knowledge to transmute all matter into solid gold.

Choose a creature you can see within range. At the start of the creature's next turn, it must make a Constitution saving throw. On a failure, it is Restrained, as its flesh starts to harden and permanently turn to gold. On a success, the creature is unaffected, and the spell ends.

If a creature fails its first saving throw, it must make another Constitution saving throw at the start of each of its turns - if it succeeds on its saving throws two more times, it remains Restrained. If the creature fails its saving throw twice, it is Petrified, and permanently turns to gold. 

All conditions from this spell can only be removed by a Wish spell, or similarly powerful magic.