The discovery pushes back the date for the first use of metallic ink by several centuries. The Herculaneum scrolls were buried by the eruption of Mount Vesuvius in 79 A.D. and are charred and fragile. Previous efforts to read them, over many centuries, has damaged or destroyed some of the scrolls.
BBC News article by Helen Briggs here.
An Eruption of Vesuvius Seen from Portici by Joseph Wright, c. 1774-76.