Stasis Stone

This small, crystalline, purple stone measures 3/4 of an inch in diameter and weighs an ounce. Typically, 1d4 + 2 *stasis stones* can be found together. You can use an action to throw the stone up to 30 feet. The stone explodes on impact and is destroyed. Each creature within a 10-foot radius of where the stone landed must succeed on a DC 15 Constitution saving throw or be petrified until the end of its next turn as the stone releases temporal magic and freezes it in time.

Source: Tome of Heroes · OGL-1.0a · 5.1