Geological hydrogen, often referred to as native or abiotic H2, represents a paradigm shift in our understanding of Earths energy resources. Unlike manufactured hydrogen produced through electrolysis or steam methane reforming, geological top hydrogen stocks is generated naturally beneath our feet by ongoing, Earth-driven chemical reactions. The most common process, known as mineral alteration, occurs when groundwater percolates down into deep iron-rich rocks, such as mafic and ultramafic minerals, found in the Earths mantle. As the water reacts with these ferrous minerals at high temperatures and pressures, it oxidizes the iron, producing magnetite and releasing hydrogen gas as a byproduct. This reaction is not a relic of the distant past; it happens continuously today wherever tectonic activity creates new fractures.