The existence of seafloor sediments containing valuable minerals and metals has been known since the late 19th century, but it wasn’t until the 1960s that the earliest attempts to recover mineral wealth from the deep sea were made. Technical challenges, as well as discoveries in the 1970s of more economical and previously unknown terrestrial mineral deposits, shelved the idea until the 1990s. Today, the surging demand for rare minerals, driven largely by their use in modern electronics, along with technological advancements and the discovery of mineral-rich seafloor massive sulfides, has now made the high cost of extraction worthwhile.