The Iron Age is the final epoch of the three-age system, preceded by the Stone Age and the Bronze Age. The technology of the Iron Age is characterised by the production of tools and weaponry by ferrous metallurgy, more specifically from carbon steel.
The Celtic spiral is a dynamic and popular symbol, indicative of endless movement and in use from the Neolithic period (circa 5000 BC). Bronze craftsmen continued to use the pattern during the Bronze Age, though more flamboyant and flatter spiral patterns were favoured.