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oolite

(Encyclopedia)oolite ōˈəlīt, ōˈō– [key], rock composed of small concretions, usually of calcium carbonate, containing a nucleus and clearly defined concentric shells. In the British Isles oolitic limestone...

alkaline earths

(Encyclopedia)alkaline earths ălˈkəlīn, –lĭn [key], oxides of the alkaline-earth metals, especially of calcium, strontium, and barium. They are not readily soluble in water and form solutions less basic than...

bone meal

(Encyclopedia)bone meal, finely ground bone used as a fertilizer for its content of phosphate and nitrogen (about 23%–30% available phosphate and 2%–4% nitrogen); it is an expensive form of phosphoric acid when...

hardpan

(Encyclopedia)hardpan, condition of the soil or subsoil in which the soil grains become cemented together by such bonding agents as iron oxide and calcium carbonate, forming a hard, impervious mass. It is disadvant...

limestone

(Encyclopedia)limestone, sedimentary rock wholly or in large part composed of calcium carbonate. It is ordinarily white but may be colored by impurities, iron oxide making it brown, yellow, or red and carbon making...

mineral, dietary

(Encyclopedia)mineral, dietary, any of a group of inorganic elements that are essential to humans and animals for normal body function. In nutrition, minerals are those elements for which the body's requirement is ...

whiting, powdery substance

(Encyclopedia)whiting, white, powdery substance, prepared by grinding chalk or some other source of calcium carbonate. When mixed with linseed oil it forms putty, and with water and several other substances it cons...

scheelite

(Encyclopedia)scheelite shāˈlīt, shēˈ– [key], heavy white or yellow mineral, calcium tungstate, CaWO4, crystallizing in the tetragonal system. It is found in granite pegmatites, in contact-metamorphic deposi...

hydrate

(Encyclopedia)hydrate hīˈdrāt [key], chemical compound that contains water. A common hydrate is the familiar blue vitriol, a crystalline form of cupric sulfate. Chemically, it is cupric sulfate pentahydrate, CuS...

hypertension

(Encyclopedia)hypertension or high blood pressure, elevated blood pressure resulting from an increase in the amount of blood pumped by the heart or from increased resistance to the flow of blood through the small a...