Miltos is a red mineral substance, which was rare and thus valuable in the ancient Greece.
The island of Keos was the main source of miltos and the economy of Koressia, the main city of the island, was dependable on the pigment. The substance was used to paint triremes to help maintain them, and for this reason Athens especially was after the substance.
During the Peloponnesian War, the Spartan misthios Kassandra learned about a missing miltos cargo, and investigated. She found the shipwreck and its shipment of miltos near the Wailing Cavern around the island of Lestris.
- μίλτος (míltos) is Greek word denoting 'red', 'ochre', and even 'blood'.