#rock

• Aubrieta deltoidea — The type species of perennial flowering plant in the genus Aubrieta, family Brassicaceae, native to southeastern Europe and widely cultivated as an ornamental; Lilac bush or rock cress. It is characterized by low-growing, mat-forming habits, slightly toothed deltoid leaves, and abundant violet or pink-purple flowers covering the foliage in early spring.
• Augitite — An effusive, ultrabasic, and melanocratic igneous rock, completely lacking feldspars, composed primarily of large augite and magnetite crystals embedded in a glassy or microcrystalline basaltic groundmass. In structural geology, it represents a rare variety of volcanic pyroxenite.
• Aurolite — A rare scientific or commercial term used to describe a type of rock, mineral aggregate, or natural crystalline glass containing microscopic gold inclusions or pyritic compounds that give it an intense internal golden glow.
• Authigenesis — The geological process of in situ formation of new minerals within a sedimentary rock or sediment, during diagenesis or epigenesis, through chemical reactions, precipitation, or fluid interactions, without input of transported material.
• Self-detachment — The act of self-detaching and its result; an automated or mechanical process through which a component, module, rocket stage, or auxiliary system separates autonomously from the main body, as a result of a preprogrammed electronic impulse or upon reaching critical physical parameters, without the manual intervention of an operator.
• Autolith — Fragments of early igneous rock incorporated into a younger igneous rock mass, both originating from the same parent magma or deep magmatic chamber. Also known as cognate inclusions or autoliths, these petrographic structures represent portions crystallized at the beginning of the cooling process, which were later detached and engulfed by the remaining fluid magmatic flow, providing crucial data on the chemical evolution of the magmatic reservoir.
• Autometamorphism — A geological process of mineralogical transformation and alteration of an igneous rock, caused in the final stages of its consolidation by its own residual gases, water vapor, and hydrothermal solutions released during magma cooling. This phenomenon transforms unstable primary minerals into new secondary assemblages (such as serpentinization or chloritization of basalts) without the input of external tectonic pressures or temperatures.
• Automorphic — Regarding minerals or crystals, having their own regular, well-developed geometric shapes, bounded by plane crystalline faces reflecting the internal symmetrical structure of the atomic lattice, without being modified or restricted by space constraints from neighboring minerals. In petrography, the term describes the first minerals that separate and solidify from an igneous melt, having full freedom of structural growth within the fluid residual liquid.
• Self-propulsion — The act of self-propelling and its result; a technical or mechanical process through which a vehicle, projectile, or body generates its force of motion and spatial displacement utilizing an internal energy source or its own engine, without the input of an external pulling or pushing force. This structural system is fundamental in the design of rockets, spacecraft, submarines, and heavy self-propelled machinery, optimizing the operational independence of the assembly.
• Aventurine stone — A feminine variant used in the commercial jargon of jewelers and in practical gemology to denote the semi-precious stone aventurine, praised for its aesthetic and decorative properties; it refers specifically to pieces polished as cabochons or beads used in manufacturing necklaces, amulets, and ornaments. In lithotherapy, the term is traditionally associated with emotional balance, luck, and prosperity.
• Bafflestone texture — A type of autochthonous carbonate sedimentary rock (limestone), according to the revised Dunham classification (Embry and Klovan), where the original organic components (such as fan-shaped corals or calcareous algae) grew together during deposition, acting as baffles that slowed down water flow and trapped fine sediment.
• Baikonur — The world's oldest and largest operational space launch facility, located in the desert steppe of Kazakhstan, currently leased and administered by the Russian Federation. Founded in the 1950s as a Soviet military test site, it achieved global fame for launching the first artificial satellite (Sputnik 1) and the first human spaceflight (Yuri Gagarin).
• Ballad — A species of the epic genre (in popular or cultivated literature) in verse, of relatively large dimensions, with a simple plot and a small number of characters, narrating a heroic action, a historical or legendary event, or a fantastic drama from the past. In music, it designates an instrumental or vocal composition with a dramatic, narrative, and romantic lyrical character, or a slow, sentimental song specific to modern pop and rock music.