Infusion Stone of Poison

Toxic Pebble. You can place this tiny stone into a vial of water to infuse it with poison. If it remains in the vial for one week, the stone is fully dissolved, turning the water into a vial of Alchemist’s Poison. You can use this poison to coat one slashing or piercing weapon, or up to three pieces of ammunition. Applying the poison takes one action. Once applied, the poison remains potent for 1 minute. A creature hit by a poisoned weapon or piece of ammunition must make a Constitution saving throw (DC 12), taking 2d4 poison damage on a failed save, or half as much on a successful one. If the vial remains sealed for longer after the stone is added, the poison grows more potent: After one month, the DC increases to 14 and the damage becomes 4d4. After one year, the DC becomes 16 and the damage 8d4. After ten years, the DC becomes 18 and the damage 16d4.