The oldest rocks of Elba consist of schist and serpentine which in the eastern part of the island are overlaid by beds containing Silurian and Devonian fossils.
The most remarkable feature in the geology of Elba is the extent of the granitic and ophiolitic eruptions of the Tertiary period.
The celebrated iron ore of Elba is of Tertiary age and occurs indifferently in all the older rocks.
Elba was famous for its mines in early times, and the smelting furnaces gave it its Greek name of A' OaNia ("soot island").
In 453 B.C. Elba was devastated by a Syracusan squadron.