Rock (geology) in the context of "Ring (jewellery)"

The natural environment or natural world encompasses all biotic and abiotic things occurring naturally, meaning in this case not artificial. The term is most often applied to Earth or some parts of Earth. This environment encompasses the interaction of all living species, climate, weather and natural resources that affect human survival and economic activity.The concept of the natural environment can be distinguished as components:

• Complete ecological units that function as natural systems without massive civilized human intervention, including all vegetation, microorganisms, soil, rocks, plateaus, mountains, the atmosphere and natural phenomena that occur within their boundaries and their nature.
• Universal natural resources and physical phenomena that lack clear-cut boundaries, such as air, water and climate, as well as energy, radiation, electric charge and magnetism, not originating from civilized human actions.

In contrast to the natural environment is the built environment. Built environments are where humans have fundamentally transformed landscapes such as urban settings and agricultural land conversion, the natural environment is greatly changed into a simplified human environment. Even acts which seem less extreme, such as building a mud hut or a photovoltaic system in the desert, the modified environment becomes an artificial one. Though many animals build things to provide a better environment for themselves, they are not human, hence beaver dams and the works of mound-building termites are thought of as natural.

A coast (also called the coastline, shoreline, or seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, such as that caused by waves. The geological composition of rock and soil dictates the type of shore that is created. Earth has about 620,000 km (390,000 mi) of coastline.

Coasts are important zones in natural ecosystems, often home to a wide range of biodiversity. On land, they harbor ecosystems, such as freshwater or estuarine wetlands, that are important for birds and other terrestrial animals. In wave-protected areas, coasts harbor salt marshes, mangroves, and seagrasses, all of which can provide nursery habitat for finfish, shellfish, and other aquatic animals. Rocky shores are usually found along exposed coasts and provide habitat for a wide range of sessile animals (e.g. mussels, starfish, barnacles) and various kinds of seaweeds.

The Stone Age was a broad prehistoric period during which stone was widely used to make stone tools with an edge, a point, or a percussion surface. The period lasted for roughly 3.4 million years and ended between 4000 BC and 2000 BC, with the advent of metalworking. Because of its enormous timescale, it encompasses 99% of human history.

Though some simple metalworking of malleable metals, particularly the use of gold and copper for purposes of ornamentation, was known in the Stone Age, it is the melting and smelting of copper that marks the end of the Stone Age. In Western Asia, this occurred by about 3000 BC, when bronze became widespread. The term Bronze Age is used to describe the period that followed the Stone Age, as well as to describe cultures that had developed techniques and technologies for working copper alloys (bronze: originally copper and arsenic, later copper and tin) into tools, supplanting stone in many uses.

A tumulus (pl.: tumuli) is a mound of earth and stones raised over a grave or graves. Tumuli are also known as barrows, burial mounds, mounds, howes, or in Siberia and Central Asia as kurgans, and may be found throughout much of the world. A cairn, which is a mound of stones built for various purposes, may also originally have been a tumulus.

Tumuli are often categorised according to their external apparent shape. In this respect, a long barrow is a long tumulus, usually constructed on top of several burials, such as passage graves. A round barrow is a round tumulus, also commonly constructed on top of burials. The internal structure and architecture of both long and round barrows have a broad range; the categorization only refers to the external apparent shape.

A tool is an object that can extend an individual's ability to modify features of the surrounding environment or help them accomplish a particular task, and proto-typically refers to solid hand-operated non-biological objects with a single broad purpose that lack multiple functions, unlike machines or computers. Although human beings are proportionally most active in using and making tools in the animal kingdom, as use of stone tools dates back hundreds of millennia, and also in using tools to make other tools, many animals have demonstrated tool use in both instances.

Early human tools, made of such materials as stone, bone, and wood, were used for the preparation of food, hunting, the manufacture of weapons, and the working of materials to produce clothing and useful artifacts and crafts such as pottery, along with the construction of housing, businesses, infrastructure, and transportation. The development of metalworking made additional types of tools possible. Harnessing energy sources, such as animal power, wind, or steam, allowed increasingly complex tools to produce an even larger range of items, with the Industrial Revolution marking an inflection point in the use of tools. The introduction of widespread automation in the 19th and 20th centuries allowed tools to operate with minimal human supervision, further increasing the productivity of human labor.

Stoneware is a broad class of pottery fired at a relatively high temperature, to be impervious to water. A modern definition is a vitreous or semi-vitreous ceramic made primarily from stoneware clay or non-refractory fire clay. This definition excludes stone vessels that are carved from a solid chunk of stone. End applications of stoneware include tableware and decorative ware such as vases.

Stoneware is fired at between about 1,100 °C (2,010 °F) to 1,300 °C (2,370 °F). Historically, reaching such temperatures was a long-lasting challenge, and temperatures somewhat below these were used for a long time.

Tiles are usually thin, square or rectangular coverings manufactured from hard-wearing material such as ceramic, stone, metal, baked clay, or even glass. They are generally fixed in place in an array to cover roofs, floors, walls, edges, or other objects such as tabletops. Alternatively, tile can sometimes refer to similar units made from lightweight materials such as perlite, wood, and mineral wool, typically used for wall and ceiling applications. In another sense, a tile is a construction tile or similar object, such as rectangular counters used in playing games (see tile-based game). The word is derived from the French word tuile, which is, in turn, from the Latin word tegula, meaning a roof tile composed of fired clay.

Tiles are often used to form wall and floor coverings, and can range from simple square tiles to complex or mosaics. Tiles are most often made of ceramic, typically glazed for internal uses and unglazed for roofing, but other materials are also commonly used, such as glass, cork, concrete and other composite materials, and stone. Tiling stone is typically marble, onyx, granite or slate. Thinner tiles can be used on walls than on floors, which require more durable surfaces that will resist impacts.

Plastic arts are art forms which involve physical manipulation of a plastic medium, such as clay, wax, paint – or even plastic in the modern sense of the word (a ductile polymer) – to create works of art. The term is used more generally to refer to the visual arts (such as painting, sculpture, ceramics, architecture, film and photography), rather than literature and music. Materials for use in the plastic arts, in the narrower definition, include those that can be carved or shaped, such as stone or wood, concrete, glass, or metal.