Niter | |
---|---|
General | |
Category | Nitrates, oxide mineral |
Formula (repeating unit) | KNO3 |
IMA symbol | Nit [1] |
Strunz classification | 5.NA.10 |
Dana classification | 18.1.2.1 |
Crystal system | Orthorhombic |
Crystal class | Dipyramidal (mmm) H-M symbol: (2/m 2/m 2/m) |
Space group | Cmc21 |
Identification | |
Color | White |
Crystal habit | Druse or acicular |
Cleavage | Very good on {001}; good on {010} |
Fracture | Brittle |
Mohs scale hardness | 2 |
Luster | Vitreous |
Streak | White |
Diaphaneity | Transparent |
Specific gravity | 2.10 (calc.) |
Solubility | Soluble |
References | [2] [3] [4] |
Niter or nitre [5] is the mineral form of potassium nitrate, KNO3. It is a soft, white, highly soluble mineral found primarily in arid climates or cave deposits.
Historically, the term niter was not well differentiated from natron, both of which have been very vaguely defined but generally refer to compounds of sodium or potassium joined with carbonate or nitrate ions.
Niter is a colorless to white mineral crystallizing in the orthorhombic crystal system. It is the mineral form of potassium nitrate, KNO3, [6] and is soft (Mohs hardness 2), [7] highly soluble in water, [6] and easily fusible. Its crystal structure resembles that of aragonite, with potassium replacing calcium and nitrate replacing carbonate. [8] It occurs in the soils of arid regions and as massive encrustations and efflorescent growths on cavern walls and ceilings where solutions containing alkali potassium and nitrate seep into the openings. [6] It occasionally occurs as prismatic acicular crystal groups, and individual crystals commonly show pseudohexagonal twinning on [110]. Niter and other nitrates can also form in association with deposits of guano and similar organic materials. [7]
Niter as a term has been known since ancient times, although there is much historical confusion with natron (an impure sodium carbonate/bicarbonate), and not all of the ancient salts known by this name or similar names in the ancient world contained nitrate. [6] The name is from the Ancient Greek νιτρωνnitron from Ancient Egyptian netjeri, related to the Hebrew néter, for salt-derived ashes (their interrelationship is not clear). [9]
The Hebrew néter may have been used as, or in conjunction with soap, as implied by Jeremiah 2:22, "For though thou wash thee with niter, and take thee much soap..." However, it is not certain which substance (or substances) the Biblical "neter" refers to, with some suggesting sodium carbonate. [10]
The Neo-Latin word for sodium, natrium, is derived from this same class of desert minerals called natron (French) [11] from Spanish natrón through Greek νίτρον (nitron), derived from Ancient Egyptian netjeri, referring to the sodium carbonate salts occurring in the deserts of Egypt, not the nitratine (nitrated sodium salts) typically occurring in the deserts of Chile (classically known as "Chilean saltpeter" and variants of this term). [9] [12] [ self-published source? ]
A term (ἀφρόνιτρον, aphronitron or aphronitre) which translates as "foam of niter" was a regular purchase in a fourth-century AD series of financial accounts, and since it was expressed as being "for the baths" was probably used as soap. [13]
Niter was used to refer specifically to nitrated salts known as various types of saltpeter (only nitrated salts were good for making gunpowder) by the time niter and its derivative nitric acid were first used to name the element nitrogen, in 1790. [14]
Because of its ready solubility in water, niter is most often found in arid environments and often in conjunction with other soluble minerals like halides, iodates, borates, gypsum, and rarer carbonates and sulphates. [15] [16] Potassium and other nitrates are of great importance for use in fertilizers and, historically, gunpowder. Much of the world's demand is now met by synthetically produced nitrates, though the natural mineral is still mined and is still of significant commercial value. [17] [18]
Niter occurs naturally in certain places like the "Caves of Salnitre" (Collbató) known since the Neolithic. In the "Cova del Rat Penat", guano (bat excrements) deposited over thousands of years became saltpeter after being leached by the action of rainwater.[ citation needed ]
In 1783, Giuseppe Maria Giovene and Alberto Fortis together discovered a "natural nitrary" in a doline close to Molfetta, Italy, named Pulo di Molfetta. The two scientists discovered that niter formed inside the walls of the caves of the doline, under certain conditions of humidity and temperature. [19] After the discovery, it was suggested that manure could be used for agriculture, in order to increase the production, rather than to make gunpowder. [20] The discovery was challenged by scholars until chemist Giuseppe Vairo and his pupil Antonio Pitaro confirmed the discovery. Naturalists sent by academies from all Europe came in large number to visit the site; since niter is a fundamental ingredient in the production of gunpowder, these deposits were of considerable strategic interest. [21] : 8–10 The government started extraction. Shortly thereafter, Giovene discovered niter in other caves of Apulia. [21] : 9–10 [22] The remnants of the extraction plant is a site of industrial archaeology, although currently not open to tourists. [23]
Related minerals are soda niter (sodium nitrate), ammonia niter or gwihabaite (ammonium nitrate), nitrostrontianite (strontium nitrate), nitrocalcite (calcium nitrate), nitromagnesite (magnesium nitrate), nitrobarite (barium nitrate) and two copper nitrates, gerhardtite and buttgenbachite; in fact all of the natural elements in the first three columns of the periodic table and numerous other cations form nitrates which are uncommonly found for the reasons given, but have been described. Niter was used to refer specifically to nitrated salts known as various types of saltpeter (only nitrated salts were good for making gunpowder) by the time niter and its derivative nitric acid were first used to name the element nitrogen, in 1790.[ citation needed ]
A carbonate is a salt of carbonic acid, H2CO3, characterized by the presence of the carbonate ion, a polyatomic ion with the formula CO2−3. The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate groupO=C(−O−)2.
Nitrate is a polyatomic ion with the chemical formula NO−
3. Salts containing this ion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all inorganic nitrates are soluble in water. An example of an insoluble nitrate is bismuth oxynitrate.
Potassium is a chemical element; it has symbol K and atomic number 19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure. It was first isolated from potash, the ashes of plants, from which its name derives. In the periodic table, potassium is one of the alkali metals, all of which have a single valence electron in the outer electron shell, which is easily removed to create an ion with a positive charge. In nature, potassium occurs only in ionic salts. Elemental potassium reacts vigorously with water, generating sufficient heat to ignite hydrogen emitted in the reaction, and burning with a lilac-colored flame. It is found dissolved in seawater, and occurs in many minerals such as orthoclase, a common constituent of granites and other igneous rocks.
Potash includes various mined and manufactured salts that contain potassium in water-soluble form. The name derives from pot ash, plant ashes or wood ash soaked in water in a pot, the primary means of manufacturing potash before the Industrial Era. The word potassium is derived from potash.
Potassium nitrate is a chemical compound with a sharp, salty, bitter taste and the chemical formula KNO
3. It is an ionic salt of potassium ions K+ and nitrate ions NO3−, and is therefore an alkali metal nitrate. It occurs in nature as a mineral, niter (or nitre outside the US). It is a source of nitrogen, and nitrogen was named after niter. Potassium nitrate is one of several nitrogen-containing compounds collectively referred to as saltpeter (or saltpetre outside the US).
Natron is a naturally occurring mixture of sodium carbonate decahydrate (Na2CO3·10H2O, a kind of soda ash) and around 17% sodium bicarbonate (also called baking soda, NaHCO3) along with small quantities of sodium chloride and sodium sulfate. Natron is white to colourless when pure, varying to gray or yellow with impurities. Natron deposits are sometimes found in saline lake beds which arose in arid environments. Throughout history natron has had many practical applications that continue today in the wide range of modern uses of its constituent mineral components.
Sodium carbonate is the inorganic compound with the formula Na2CO3 and its various hydrates. All forms are white, odourless, water-soluble salts that yield alkaline solutions in water. Historically, it was extracted from the ashes of plants grown in sodium-rich soils, and because the ashes of these sodium-rich plants were noticeably different from ashes of wood, sodium carbonate became known as "soda ash". It is produced in large quantities from sodium chloride and limestone by the Solvay process, as well as by carbonating sodium hydroxide which is made using the chloralkali process.
An evaporite is a water-soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution. There are two types of evaporite deposits: marine, which can also be described as ocean deposits, and non-marine, which are found in standing bodies of water such as lakes. Evaporites are considered sedimentary rocks and are formed by chemical sediments.
Sodium nitrate is the chemical compound with the formula NaNO
3. This alkali metal nitrate salt is also known as Chile saltpeter to distinguish it from ordinary saltpeter, potassium nitrate. The mineral form is also known as nitratine, nitratite or soda niter.
Potassium sulfate (US) or potassium sulphate (UK), also called sulphate of potash (SOP), arcanite, or archaically potash of sulfur, is the inorganic compound with formula K2SO4, a white water-soluble solid. It is commonly used in fertilizers, providing both potassium and sulfur.
Thermonatrite is a naturally occurring evaporite mineral form of sodium carbonate, Na2CO3·H2O.
Caliche is a sedimentary rock, a hardened natural cement of calcium carbonate that binds other materials—such as gravel, sand, clay, and silt. It occurs worldwide, in aridisol and mollisol soil orders—generally in arid or semiarid regions, including in central and western Australia, in the Kalahari Desert, in the High Plains of the western United States, in the Sonoran Desert, Chihuahuan Desert and Mojave Desert of North America, and in eastern Saudi Arabia at Al-Hasa. Caliche is also known as calcrete or kankar. It belongs to the duricrusts. The term caliche is borrowed from Spanish and is originally from the Latin word calx, meaning lime.
Potassium nitrite (distinct from potassium nitrate) is the inorganic compound with the chemical formula KNO2. It is an ionic salt of potassium ions K+ and nitrite ions NO2−, which forms a white or slightly yellow, hygroscopic crystalline powder that is soluble in water.
Nitratine or nitratite, also known as cubic niter (UK: nitre), soda niter or Chile saltpeter (UK: Chile saltpetre), is a mineral, the naturally occurring form of sodium nitrate, NaNO3. Chemically it is the sodium analogue of saltpeter. Nitratine crystallizes in the trigonal system, but rarely occurs as well-formed crystals. It is isostructural with calcite. It is relatively soft and light with a Mohs hardness of 1.5 to 2 and a specific gravity of 2.24 to 2.29. Its refractive indices are nω = 1.587 and nε = 1.336.
Potassium nitrate is an oxidizer so storing it near fire hazards or reducing agents should be avoided to minimise risk in case of a fire.
Although, in modern usage, the word “nitre” usually refers to the mineral form of potassium nitrate, it may also refer to a variety of other minerals and chemical compounds, including
A saltpetre works or nitrary is a place of production of potassium nitrate or saltpetre used primarily for the manufacture of gunpowder. The saltpeter occurs naturally in certain places like the "Caves of Salnitre" (Collbató) known since the Neolithic. In the "Cova del Rat Penat", guano deposited over thousands of years became saltpeter after being leached by the action of rainwater.
The Confederate Nitre and Mining Bureau was a civilian government bureau to provide the Confederate States of America with needed materials such as copper, iron, lead, saltpeter, sulfur, zinc, and other metals. The Bureau oversaw civilian contracts and offered advice, instruction and guidance in the production of these materials. The Nitre and Mining Bureau was also known as the "CSNMB", the "Bureau of Nitre" or the "Nitre Bureau". The Niter and Mining Corps was the military division of the Bureau. The Nitre and Mining Bureau was part of the Confederate Ordnance Department, under the supervision of General Josiah Gorgas. The Nitre and Mining Bureau was supervised by General Isaac M. St. John. The Central Ordinance Laboratory was headed by John Mallet.
Giuseppe Maria Giovene was an Italian archpriest, naturalist, agronomist, geologist, meteorologist, entomologist and ichthyologist. He is best known for his studies on the "nitrosity" of Pulo di Molfetta, which made him famous abroad, so as to be cited and appreciated by many Italian and foreign scholars, including Eberhard August Wilhelm von Zimmermann in a French publication.