You searched for: “geodic
geodic
Descriptive of a small, hollow, usually rounded rock, lined on the inside with inward-pointing crystals.

Such related geodes form when mineral-rich water entering a cavity in a rock undergoes a sudden change in pressure or temperature, causing crystals to form from the solution and line the cavity's walls.

This entry is located in the following units: geo-, ge- + (page 8) -ic (page 57)