Mercury primarily comes from natural geological sources in the Earth's crust. The most common natural form of mercury is found in the mineral cinnabar (mercury sulfide), which can contain up to 86% mercury. Cinnabar deposits have been mined historically in places such as Spain, China, Kyrgyzstan, and Algeria
. Natural processes such as volcanic eruptions, weathering of rocks, and undersea vents release mercury from the Earth's crust into the environment, where it can enter soil, water, and the atmosphere
. Mercury is also naturally present in fossil fuels like coal, crude oil, and other minerals due to its absorption by ancient plants and geological processes
. In addition to these natural sources, human activities contribute significantly to mercury emissions. These include burning coal, metal extraction, cement production, and small-scale gold mining, which release mercury into the atmosphere and environment
. Historically, ancient civilizations obtained mercury by mining cinnabar ore and extracting liquid mercury through heating and processing techniques known since Neolithic times
. In summary, mercury originates mainly from cinnabar mineral deposits in the Earth's crust, volcanic and geological activity, and is also released through human industrial activities worldwide
