A precious stone blessed by light.
Sun stones are activated by striking them against a surface. They then glow with a warm light that spreads out to 30 feet for 1 hour. This light is considered sunlight, and affects creatures harmed by sunlight.
A typical stone had a base value of 10 gp
The most common variety of this ornamental stone was soft and only able to be cut cabochon, but it did occur in a colorless or slightly greenish variety that was facet grade. Cabochons of sunstone were rarely more than three-quarters of an inch (2 cm) in diameter and had glittering red or orange inclusions that were suspended in a nearly colorless matrix, giving the overall stone a warm golden or reddish brown hue. A typical stone had a base value of 10 gp.
Sunstones were considered sacred by followers of Horus-Re, Labelas Enoreth, and Sehanine Moonbow—appropriate for sacrifice, or to be consecrated for use, or recognized as boons or omens when found.