In
geology, rods are
cylindrical structures of a single
mineral in a
deformed rock.
Similiar in form to boudins and mullions, but distinguished by their monomineralic (single mineral) composition. Commonly composed of quartz, but rods of calcite and pyrite have been described.
Rods are most likely formed by the deformation of mineral segregations or the elongation of conglomerate clasts.