Natural hydrogen
Molecular hydrogen naturally occurring on Earth
Natural hydrogen (also known as white hydrogen, geologic hydrogen, geogenic hydrogen, or gold hydrogen) is molecular hydrogen present on Earth that is formed by natural processes, as opposed to hydrogen produced in a laboratory or in industry. Modelling suggests that sufficient natural hydrogen exists to meet humanity's demand for thousands of years; however, most of it cannot be extracted economically. Natural hydrogen has been identified in many source rocks in areas beyond the sedimentary basins where oil companies typically operate.
From Wikipedia, under CC BY-SA. More on occurri.