mineral

Manganese Nodule

Polymetallic Nodule (Hydrous manganese and iron oxides)

AI-generated identification · may be incorrect

Hardness varies from 1.5 to 3 on the Mohs scale, color ranges from dark brown to black, dull to earthy luster, amorphous or microcrystalline structure, specific gravity around 2.0 to 3.0.

Identified July 28, 2026More mineral →

Explore Manganese Nodule in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness varies from 1.5 to 3 on the Mohs scale, color ranges from dark brown to black, dull to earthy luster, amorphous or microcrystalline structure, specific gravity around 2.0 to 3.0.

Formation & geological history

Formed through hydrogenetic and diagenetic processes on the deep-ocean floor over millions of years by the slow precipitation of manganese and iron oxides around a core.

Uses & applications

Studied as a potential source of critical metals such as nickel, copper, cobalt, and rare earth elements for industrial and technology manufacturing.

Geological facts

These potato-sized metallic lumps cover vast areas of the abyssal plains, particularly in the Clarion-Clipperton Zone of the Pacific Ocean at depths of 4,000 to 6,000 meters.

Field identification & locations

Identified by their dark, roughly spherical nodular shape found exclusively in deep marine environments; highly sought after by specialized research and mineral collectors.