pf2e.fyi
From Pathfinder Advanced Player's Guide, which isn't enabled.

Magic Stone

SPELL 1
CONCENTRATEMANIPULATEVITALITY
Traditions divine, primal
Cast to
Range touch
Targets 1 to 3 non-magical stones or sling bullets
Duration 1 minute

You pour vitality energy into ordinary stones, granting them temporary magical properties. You can target 1 non-magical stone or sling bullet for every action you use Casting this Spell. The stones must be unattended or carried by you or a willing ally. The stones become +1 striking disrupting Sling Bullets. Each stone can be used only once, after which it crumbles to dust.

Spell Effect: Magic Stone

Pathfinder Advanced Player's GuideOGL