Sol's Searing Orb

This spell must be cast upon a topaz. When the spell is complete, the stone glows with an inner light. The gem must be immediately thrown at an opponent, for it quickly becomes too hot to hold. (The acts of casting and throwing occur in the same round.) It is not possible for the priest to give the stone to another character to throw.
The stone can be hurled up to 30 yards. The priest must roll normally to hit; he gains a +3 bonus to his attack roll and suffers no penalty for nonweapon proficiency. In addition, the glowing gem is considered a +3 weapon for determining whether a creature can be struck (creatures hit only by magical weapons, for example). There is no damage bonus, however.
When it hits, the gem bursts with a brilliant, searing flash that causes 6d6 points of fire damage to the target and blinds him for 1d6 rounds. The victim is allowed a saving throw vs. spell. If successful, only half damage is sustained and the target is not blinded. Undead creatures suffer 12d6 points of damage and are blinded for 2d6 rounds (if applicable) if their save is failed. They receive 6d6 points of damage and are blinded for 1d6 rounds if the save is successful.
If the gem misses its target, it explodes immediately, causing 3d6 points of damage (or 6d6 against undead) to all creatures within a 3' radius. It blinds them for 1d3 rounds (1d6 rounds vs. undead). All victims are allowed a saving throw vs. spell, with success indicating half damage and no blindness. The DM should use the rules for grenade-like missiles found in the DUNGEON MASTER Guide for determining where the stone hits.

[Tome ofg Magic]

Sphere: Sun
(Invocation)
Level: 6

Range: 30 yards
Components: V, S, M
Duration: Instantaneous
Casting Time: 6
Area of Effect: One gem
Saving Throw: Special

Material Components:
a topaz gemstone worth at least 500 gp