Rockforming

Rockforming refers to the natural processes by which rocks are formed, altered, and assembled in the Earth's crust. Rocks are traditionally classified into three broad groups by origin: igneous, sedimentary, and metamorphic. The term also encompasses rock‑forming minerals, such as feldspar, quartz, calcite, and mica, which commonly make up crustal rocks.

Igneous rocks form by crystallization from molten rock. Intrusive (plutonic) rocks like granite crystallize below the surface, producing coarse textures, while extrusive (volcanic) rocks such as basalt and rhyolite erupt at the surface and cool rapidly to form fine textures. Sedimentary rocks originate from weathered and eroded fragments that are transported, deposited, compacted, and cemented (lithified), or from the direct precipitation of minerals from water, yielding rocks such as sandstone, limestone, coal, and evaporites. Metamorphic rocks develop when existing rocks are altered by heat, pressure, and chemically active fluids, reorganizing minerals and textures to form materials such as marble and schist.

These pathways are interconnected in the rock cycle, a conceptual model describing how any rock type can transform into another under varying conditions of tectonics, burial, uplift, erosion, and magmatic activity. The study of rockforming processes supports understanding crustal composition, mineral resources, and the geological history of Earth.