Roccia

Roccia, the Italian word for rock, refers to a natural solid aggregate composed of minerals or mineraloids. In geology, rocks form the solid outer layer of the Earth and vary in composition, texture, and structure.

Rocks are typically classified by their mode of formation into three broad groups: igneous, sedimentary, and metamorphic.

Igneous rocks form when molten material from inside the Earth cools and solidifies. They can crystallize underground (intrusive) with larger crystals, or erupt at the surface (extrusive) with finer or glassy textures. Common examples include granite, diorite, basalt, and obsidian.

Sedimentary rocks develop when particles or dissolved materials are transported, deposited, and lithified to form coherent rock layers. They often preserve fossils and show bedding or layering. Examples include limestone, sandstone, mudstone, and coal.

Metamorphic rocks result from the alteration of existing rocks due to high heat, pressure, or chemically active fluids, without melting. This process changes mineral composition and texture. Marble, slate, schist, and quartzite are well-known metamorphic examples.

The rock cycle describes how rocks transform through weathering, erosion, transportation, deposition, burial, metamorphism, and melting, driven by plate tectonics and surface processes. Rocks provide essential materials for construction and industry, and they record Earth history in their minerals and structures, aiding scientists in understanding past environments and geological processes.