Manganese nodules are small, round formations found on the ocean floor, primarily composed of manganese, iron, and other metals. They typically range in size from a few millimeters to several centimeters and form over millions of years through the accumulation of minerals from seawater and sediment. These nodules are of interest for their potential as a source of valuable metals, including copper, nickel, and cobalt. They are often found in deep-sea environments, particularly in areas like the Clarion-Clipperton Zone in the Pacific Ocean, where mining efforts are being explored for resource extraction.