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It is often combined as a solid solution with hydroxylapatite (Ca 5 (PO 4) 3 OH or Ca 10 (PO 4) 6 (OH) 2) in biological matrices. Chlorapatite (Ca 5 (PO 4 ) 3 Cl) is another related structure. [ 5 ] Industrially, the mineral is an important source of both phosphoric and hydrofluoric acids.
If crystals of rutile have grown in the crystal of apatite, in the right light the cut stone displays a cat's-eye effect. Major sources for gem apatite are [ 3 ] Brazil, Myanmar, and Mexico. Other sources include [ 3 ] Canada, Czech Republic, Germany, India, Madagascar, Mozambique, Norway, South Africa, Spain, Sri Lanka, and the United States.
Fluoride is classified as a weak base since it only partially associates in solution, but concentrated fluoride is corrosive and can attack the skin. Fluoride is the simplest fluorine anion . In terms of charge and size, the fluoride ion resembles the hydroxide ion.
Cubic crystals up to 20 cm across have been found at Dalnegorsk, Russia. [23] The largest documented single crystal of fluorite was a cube 2.12 meters in size and weighing approximately 16 tonnes. [24] Fluorite on barite from the Berbes mine, Ribadesella, Asturias (Spain). Fluorite crystal, 2.2 cm.
Phosphate minerals are minerals that contain the tetrahedrally coordinated phosphate (PO 3− 4) anion, sometimes with arsenate (AsO 3− 4) and vanadate (VO 3− 4) substitutions, along with chloride (Cl −), fluoride (F −), and hydroxide (OH −) anions, that also fit into the crystal structure.
The majority of their negative charges originates from hydroxyl ions, which can gain or lose a hydrogen ion (H +) in response to soil pH, in such way as to buffer the soil pH. They may have either a negative charge provided by the attached hydroxyl ion (OH − ), which can attract a cation, or lose the hydrogen of the hydroxyl to solution and ...
Fluorapatite (Ca 5 (PO 4) 3 F) is mined along with other apatites for its phosphate content and is used mostly for production of fertilizers. Most of the Earth's fluorine is bound in this mineral, but because the percentage within the mineral is low (3.5%), the fluorine is discarded as waste. Only in the United States is there significant recovery.
Nutrients in the soil are taken up by the plant through its roots, and in particular its root hairs.To be taken up by a plant, a nutrient element must be located near the root surface; however, the supply of nutrients in contact with the root is rapidly depleted within a distance of ca. 2 mm. [14] There are three basic mechanisms whereby nutrient ions dissolved in the soil solution are brought ...