limestone

a sedimentary rock consisting mainly of calcium that was deposited by the remains of marine animals

Limestone is a sedimentary rock composed largely of the mineral calcite (calcium carbonate: CaCO₃). Limestones often contain variable amounts of silica in the form of chert or flint, as well as amounts of clay, silt and sand as disseminations, nodules, or layers within the rock unit. The primary source of this calcite is most commonly marine biologymarine organisms. These organisms secrete shells that settle out of the water column and are deposited on ocean floors as Pelagic zonepelagic ooze (see lysocline for information on calcite dissolution). Secondary calcite may also be deposited by Supersaturationsupersaturated Meteorologymeteoric waters (groundwater that Precipitation (chemistry)precipitates the material in caves). This produces speleothems such as stalagmites and stalactites. Another form is composed of Ooliteoolites (oolitic limestone) and can be recognised by its granular appearance. Limestone makes up about 10 percent of the total volume of all sedimentary rocks. Pure limestones are white or almost white. Because of impurities, such as clay, sand, organic remains, iron oxide and other materials, many limestones exhibit different colors, especially on Weatheringweathered surfaces. Limestone may be crystalline, clastic, granular, or massive, depending on the method of formation. Crystals of calcite, quartz, dolomite or barite may line small cavities in the rock. Travertine is a banded, compact variety of limestone formed along streams, particularly where there are waterfalls and around Hot springhot or cold springs. Calcium carbonate is deposited where evaporation of the water leaves a solution that is supersaturated with chemical constituents of calcite. Tufa, a porous or cellular variety of travertine, is found near waterfalls. Coquina is a poorly consolidated limestone composed of pieces of coral or shells.During regional metamorphism limestone recrystallizes into marble.Limestone is a parent material of Mollisol soil group.

Uses of limestone - Limestone is especially popular in architecture, and many landmarks around the world, especially in North America and Europe, are made primarily of the material. Limestone is readily available and relatively easy to cut into blocks or more elaborate carving. It is also long-lasting and stands up well to exposure. However, it is a very heavy material, making it impractical for tall buildings; it is also quite expensive. Limestone was most popular in the early 20th and late 19th centuries. Train stations, banks and other structures from that era are normally limestone. Limestone is used as a facade on some skyscrapers, but only in thin plates for covering rather than solid blocks. In the United States, Indiana has long been noted as a source of high quality quarried building Indiana limestone, while many famous buildings in London are built from Portland limestone.Though the limestone used for construction is good for humid climates, it is vulnerable to acids, making acid rain a problem when it occurs in places where limestone is used extensively. The acids in the water can wear away the details of statues and other art.Limestone is also used to manufacture quicklime (calcium oxide).Pulverized limestone is used as a soil conditioner to neutralize acid soil conditions. Category:Sedimentary !rockscy:Calchfaende:Kalksteine o:Kalkoŝtonoet:Lubjakivifr:Ca lcairehe:אבן? גירhu:Mészkőid:Batu !kapuris:Kalksteinnja:石灰岩 ko:석회암lt:Klintisnl:Kalks teenpl:Wapieńpt:Calcárioru:� �звестнякsl:Apnenecsv: Kalkstentr:Kireç? Taşızh:石灰岩

Firesharp Design
Firesharp Design is a multidisciplinary visual arts company run by artist Nick Norris. Firesharp Design specialises in three areas of art and design - web development, fine art painting and stone sculpture.
http://www.nicknorris.com/

Quality Stone Company
The hightest Quality Stone in Texas,featuring Austin white limestone, building and landscaping stone and specialty cuts and stone art.
http://www.qualitystone.com/

HVguy.com
Aron and Justin's physics website...with some rock climbing, Texas wildlife, and backyard chemistry.
http://www.hvguy.com/

www.pietraleccese.com
Italian Limestone.
http://www.arredoinpietra.com/

MEDALLIONS AND BORDERS
We are manufacturers of all kinds of medallions and borders in our own factory in Florida, USA We can make all kinds of medallions designs between 24 to 60 as regular orders at the same price by sq/ft inside the same category (letters A, B, C or D www.medallionusa.com) bigger sizes upon request. We can make all the designs in round, square, rectangular or oval and we can use other materials like granite, ceramic, slate, glass upon request or we can make your own design or use your own materials.
http://www.medallionusa.com

Michael Barnes - Stoneworks / Germany
unique stonework for bathrooms, kitchen, house and garden
http://www.littmann-barnes.de/

Limestone College
Academics, registration, activities, and other information about this four year liberal arts college.
http://www.limestone.edu/

Limestone County
Official County Government web site.
http://www.co.limestone.al.us/

University of California Museum of Paleontology
Physically located in Berkeley, California, site contains information about exhibits, outreach, and extensive educational resources and links.
http://www.ucmp.berkeley.edu/

Limestone District School Board
Official website with details of secondary and elementary schools and adult learning centres, their programs and activities, teacher services, and related information.
http://www.limestone.on.ca/

Limestone Community High School District 130
Offers information on district board, schools, activities, events calendar and resources.
http://limestone.k12.il.us/

RootsWeb
Genealogical resource with searchable databases, family trees, mailing lists, and message boards.
http://www.rootsweb.com/