Transmute Stone to Lava

This spell turns natural rock or stone into an equal volume of magma. This spell works like all other transmute X spells except for two major differences. Creatures caught in the area of effect suffer an automatic 2d10 + 5 points of damage each round they are in the magma. Magical items that provide protection versus fire will reduce this damage by half.
All flammable items must make a save vs. magical fire or be destroyed. The only way to revert the magma back to stone is by casting a dispel magic on the area or by waiting 1d4 weeks for the magma to cool and harden. This spell is not reversible.

Joramy

Sphere: Elemental (Fire, Earth)
(Alteration, Elemental Fire & Earth)
Level: 6

Range: 100 yards
Components: V, S, M
Duration: Special
Casting Time: 9
Area of Effect: 10-foot cube/level
Saving Throw: Special

Material Components: a piece of pumice and an open flame