stoneforming

Stoneforming refers to natural processes by which minerals precipitate from solution or are deposited and accumulate to produce stone-like masses. These processes operate in a variety of settings, from sedimentary basins to karst landscapes, and can yield features ranging from small nodules to large rock bodies.

Mechanisms include cementation and precipitation of minerals from groundwater that binds sediment grains into sedimentary rock; precipitation around organic debris forming concretions; and the formation of cave and spring deposits such as travertine and other speleothems, which arise as carbonate minerals precipitate when water degasses CO2. Diagenetic processes can alter and lithify sediments over geological timescales, while biomineralization involves microorganisms that influence mineral precipitation, creating structures such as stromatolites and other stone-like laminations.

Common minerals involved are calcite (CaCO3) in limestone and travertine, silica (SiO2) in chert and opal-rich rocks, and iron oxides that form various concretions. Gypsum, dolomite, and apatite may also participate in stoneforming environments.

Stoneforming is a central concept in geology, contributing to the understanding of concretion and nodular formations, geodes, stalactites and other speleothems, and mineralized rocks that host fossils or ore deposits. It is distinct from medical stone formation in animals, such as kidney stones, which describe pathological mineralization in soft tissues.

See also: concretion, geode, stalactite, travertine, speleothem, biomineralization, diagenesis.