Eldritch Fireball

A bright purple streak flashes from you to a point you choose on a surface within range and then blossoms with shill sounding shriek into an explosion of purple fire. Each creature in a 20-foot-radius Sphere centered on that point makes a constitution saving throw, taking 5d6 Fire damage and 5d6 necrotic damage on a failed save or half as much damage on a successful one.

The explosion creates a glowing purple crater in the impact surface with a size depending on the material it is made out of at the center of the explosion.The crater glows purple and gives of a noticeable warmth for 1 minute. When a creature comes into contact with the glowing crater it makes a constitution saving throw, taking 2d6 fire damage on a failed save or half as much on a failed save.

Cloth, paper, or other soft objects: all material in the blast is destroyed.

crystal, glass, ice: 20 feet wide and 10 feet deep

wood, bone:15 feet wide and 5 feet deep

stone or soft metals:10 feet wide and 3 feet deep

iron or other durable metals: 5 feet wide and 1 foot deep

mithral: 1 foot wide and 2 inches deep

Adamantine: no crater.

Creatures within 300 feet of the center of the blast can hear the shriek of the explosion, even if they are deafened.

Using a Higher-Level Spell Slot. The Fire or Necrotic damage increases by 1d6 for each spell slot level above 4.