Dracir's Lava Surge

A strong burst of lava erupts from the ground. You pick a spot within your range and anything within 20 feet of it must make a dexterity saving throw against your dc. On a fail they take 10d12 fire damage and take 2d12 fire damage each round. On a success they take half damage and don't take damage each round. The area around it is covered by lava and any creature steps in this area takes 7d12 fire damage. This effect last 1 hour. 

After the first effect the spell the lava hardens. The type of metal in your drenched bag is the type of melted metal. They're is 10 foot cube of metal (not acutual cubed.) The metal in the bag can't be a gemstone, but can be any other type of metal. 

This spell repeats itself every day at the time casted. The only way to stop it is to dispel it, unless the caster dismisses it.