Lapindo Mudflow Review Identifies Rare Earth Potential in East Java Sediments-but Economics Remain Unproven

Highlights

• A multi-country literature review identifies neodymium, praseodymium, dysprosium, and terbium in Lapindo mudflow sediments in East Java, Indonesia.
• Reported concentrations are dominated by light REEs lanthanum and cerium, which fall within normal crustal ranges, limiting immediate economic significance.
• No mineral resource estimate, metallurgical flowsheet, or economic assessment exists—researchers call for systematic sampling and recovery testing before any commercial claims.
• Clay minerals, iron oxides, and carbonates bind REEs in the mud, meaning pH and redox changes could affect both environmental risk and potential recoverability.
• REEx classifies Lapindo as a research-stage unconventional target, not a demonstrated rare earth asset.