In terms of geology, fluorine tends to be concentrated in residual magma leading to a concentration of fluorine in some igneous rocks and in hydrothermal deposits associated with such rocks.
Most deposits mined for fluorine are hydrothermal, however, and consist of fluorine minerals that precipitated from hot water.
Fluorite has low solubility in a common range of hydrothermal temperatures, particularly from about 160 degrees Celsius (°C) down to 60 °C. The increasing fluorite solubility below 60 °C partly explains why some water with exceptionally high levels of dissolved fluorine are found even at ambient temperatures in evaporitic lake basins in some East African Rift valleys in Kenya and Tanzania.
Fluorite
is often associated with lead and silver ores; it also occurs in cavities, in sedimentary rocks, in pegmatites, and in hot-spring areas.
Fluorine occurs in many different styles of geology that have had an association with molten rock and hot ground waters. The massive copper, uranium, gold, rare earth and iron deposit Olympic Dam, in South Australia also contains 2.5 weight percent of of fluorite,amounting to approximately 106 Mt of fluorite/fluorspar.
