pedra

Pedra is the Portuguese word for stone or rock. In geology and everyday language, pedra refers to a naturally occurring solid aggregate of minerals that forms part of the Earth’s crust. The term derives from Latin petra and Greek πέτρα and is cognate with words in many Romance languages describing rock or stone.

Rocks are commonly classified by origin into three broad categories: igneous, sedimentary, and metamorphic. Igneous rocks form from the cooling and solidification of molten material, such as granite and basalt. Sedimentary rocks originate from the accumulation, compaction, and lithification of sediment; examples include sandstone and limestone. Metamorphic rocks arise from the alteration of existing rocks through heat, pressure, or chemically active fluids, with marble and schist as typical examples. Rocks can also be described by mineral composition (felsic vs mafic) and texture (grain size and porosity).

Physical properties vary widely and influence use. Hardness (Mohs scale), density, color, fracture, and porosity determine how a rock can be quarried, cut, and finished. Common applications include construction materials (stone blocks, tiles), architectural and decorative uses (statues, countertops), and industrial roles (grinding stones, aggregate for concrete).

In Portuguese-speaking contexts, pedra also appears in phrases such as pedra preciosa (precious stone) and in cultural references to materials and natural features. Access to different stones is typically regulated by mining and quarrying practices and varies by country and region.