Search results
Results From The WOW.Com Content Network
In archaeology, ground stone is a category of stone tool formed by the grinding of a coarse-grained tool stone, either purposely or incidentally. Ground stone tools are usually made of basalt, rhyolite, granite, or other cryptocrystalline and igneous stones whose coarse structure makes them ideal for grinding other materials, including plants ...
Claystone – Clastic sedimentary rock composed primarily of clay-sized particles. Coal – Combustible sedimentary rock composed primarily of carbon. Conglomerate – Sedimentary rock composed of smaller rock fragments. Coquina – Sedimentary rock that is composed mostly of fragments of shells.
In geology, rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its chemical composition, and the way in which it is formed. Rocks form the Earth's outer solid layer, the crust, and most of its interior, except for the liquid outer core and pockets of ...
Uluru (Ayers Rock) is a large sandstone formation in Northern Territory, Australia.. Sedimentary rocks can be subdivided into four groups based on the processes responsible for their formation: clastic sedimentary rocks, biochemical (biogenic) sedimentary rocks, chemical sedimentary rocks, and a fourth category for "other" sedimentary rocks formed by impacts, volcanism, and other minor processes.
Stone tools may be made of either ground stone or knapped stone, the latter fashioned by a craftsman called a flintknapper. Stone has been used to make a wide variety of tools throughout history, including arrowheads, spearheads, hand axes, and querns. Knapped stone tools are nearly ubiquitous in pre-metal-using societies because they are ...
Iolite (a gem-quality variety of cordierite) J. Benitoite (blue), joaquinite- (Ce) (brown) and neptunite (dark red) on natrolite (white), from Dallas Gem Mine area, San Benito River headwaters area, New Idria District, Diablo Range, San Benito Co., California, USA. Jacobsite. Jadarite.
Rock formations in Ongamira Valley, Sierras de Córdoba, Argentina. Belogradchik Rocks, Balkan Mountains, Bulgaria. "Jaws", an erosional fin in Little Finland, Nevada, US. "Hajdučka vrata" on Čvrsnica, Herzegovina. Paklenica, Croatia. Devil's Town, Serbia. Three Sisters in Blue Mountains, Australia. A rock formation is an isolated, scenic, or ...
Fieldstone. Fieldstone is a naturally occurring type of stone, which lies at or near the surface of the Earth. Fieldstone is a nuisance for farmers seeking to expand their land under cultivation, but at some point it began to be used as a construction material. [1][2][3] Strictly speaking, it is stone collected from the surface of fields where ...