Opal Runestone

A band of brilliant gold set with a runestone of milky opal, cut with a single rune. The rune gives off a soft white glow.

---

Ring, uncommon.

Radiant Rune. When you cast a spell that deals damage, you can change that damage to Radiant damage. You can do so with a cantrip at will. With a spell of level 1 or higher, you can do so a number of times equal to your Proficiency Bonus, and you regain all expended uses when you finish a Long Rest.

---

Homebrew rules:

Fully homebrew. It works like the Sorcerer’s Transmuted Spell, with Radiant as the only type, free on a cantrip and limited uses in place of Sorcery Points.