Frost agate

Frost Agate is an agate with white markings which resemble frost patterns. It is rare and beautiful, and is usually tumbled and polished glassy smooth. A gemcutter of unusual skill can cut the fragile stone in facets without splitting, so that at each point where facets meet (such as in a polyhedron cut, the shape of a d20), a "snowflake" of white "frost" appears. Enchanted versions of these stones are often luckstones. Lesser varieties are powdered and treated like other agates for draughts and potions. A typical stone has a base value of 10gp.