Nitratine
- Chilesalpeter
- Sodium nitrate
- Sodium nitrate
- Nitratine
Niter (English nitratine ) is a rarely occurring mineral from the mineral class of " carbonates and nitrates ." It crystallizes in the trigonal crystal system with the composition Na [ NO3 ], and is therefore a chemical point of a sodium nitrate. Since the compound is a sodium salt of nitric acid, the mineral is also referred to synonymously as sodium nitrate.
Niter rarely forms transparent and colorless, rhombohedral crystals to about three millimeters in size and glass glossy surfaces. He usually finds himself - mixed with other salts - in the form of fibrous or granular to massive mineral aggregates and stalagmites of white, yellowish or brownish color.
Special Features
Niter is readily soluble in water and more than 80 % humidity it melts. Its flavor is described as bitter, pungent and cooling.
Etymology and history
A first mention of the mineral, albeit without specific designation or indication of a chemical formula, can already be found in 1823 under the descriptions of the crystal forms of various synthetic salts of Henry James Brooke ( 1771-1857 ). Niter is described here as a rhombohedral prism in section nitrates of sodium carbonate.
Wilhelm von Haidinger coined in 1845 to today internationally recognized term nitratine for the rhombohedral sodium salt based on its membership of the nitrates and Ernst Friedrich Glocker finally laid in 1847 the customary today in the German name niter firm, which refers to the formula components nitrogen (Latin Nitrogenium ) and sodium relates.
As a type locality applies the Región de Tarapacá (I region ) in Chile, which is one of the most important reservoir for sodium nitrate, which is why the synonym Chilesalpeter arose.
Classification
In the now outdated but still in use 8th edition of the mineral classification by Strunz the niter was part of the common mineral class of " carbonates, nitrates and borates " and then to the Department of " nitrates [ NO3 ] 1 - " where he along with Gwihabait, Nitrobaryt and Nitrokalit named after him " niter - group " with the system no. V/A.01 formed.
The 9th edition used since 2001 and valid by the International Mineralogical Association (IMA ) of the Strunz'schen Mineral classification assigns the niter in the class of " carbonates and nitrates " ( borates now form a separate class ) and there is also in the Department of "nitrates" one. However, this is further subdivided according to the possible presence of Konstitionswasser ( hydroxide ) and water of crystallization, so that the mineral is "Without OH or H2O" to find according to its composition in the subdivision where it is the only member of the unnamed group 5.NA. 05 forms.
The mostly commonly used in English-speaking classification of minerals according to Dana assigns the niter as the old Strunz'sche systematics in the common class of " carbonates, nitrates and borates " and there in the department of "simple nitrates " one. Here he is the only member of the unnamed group 18:01:01 within the subdivision of a "Simple nitrates with xNO3 A · x (H2O), x may be zero " to find.
Education and Locations
Niter is formed mainly as an evaporation product under arid climate conditions, such as in dry salt lakes or groundwater leaching. However, it can also occur in seasoned bird droppings ( guano ), the organic components are weathered. Accompanying minerals occur among others epsomite, gypsum, halite, mirabilite, and Nitrocalcit Nitrokalit.
A rare mineral formation niter has been found only a few localities or in small numbers, which so far (as of 2013) about 80 localities as are known. Apart from its type locality Región de Tarapacá the mineral still occurred in Chile in several places in the Región de Antofagasta and in the quarry " Rio de la Sal " on at Caballo Muerto in the Atacama region.
Other localities lie inter alia on the Bahamas island of San Salvador, in the Autonomous Region of Xinjiang in China, the Italian community Berceto in Utsunomiya on the Japanese island of Honshu, in the Valley of Cerna in Romania, on the Crimean peninsula and in many places in different states the United States.
Crystal structure
Niter trigonal crystallized in the space group R3c ( Raumgruppen-Nr. 167) with the lattice parameters a = 5.07 Å and c = 16.82 Å and 6 formula units per unit cell.
Use
Chilean nitrate was the most important inorganic nitrogen fertilizer until it succeeded early 20th century to make using the Haber- Bosch process synthetic nitrogenous fertilizers in large quantities.