Aminoffite
{{Short description|Mineral, silicate}}
{{Use dmy dates|date=June 2024}}
{{infobox mineral
| name = Aminoffite
| category = Silicate mineral
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| image = Aminoffite-434422.jpg
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| caption = Aminoffite from Långban, Filipstad of Värmland, Sweden
| formula = Ca2(Be,Al)(Si2O7)(H2O,OH)
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| strunz = 9.BH.05
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| system = Tetragonal
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| unit cell = a = 9.8 Å, c = 9.91 Å
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| mohs = 2.5–6.0
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| references = {{cite web |title=aminoffite |website=mindat.org |url=https://www.mindat.org/min-200.html}}{{cite web |title=Aminoffite Mineral Data |url=https://webmineral.com/data/Aminoffite.shtml |website=webmineral.com}}
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Aminoffite is a mineral of the silicate class. It was first described in 1937{{cite journal |last1=Hurlbut |first1=Cornelius S. |title=Aminoffite, a new mineral from Långban |journal=Geologiska Föreningen i Stockholm Förhandlingar |date=January 1937 |volume=59 |issue=3 |pages=290–292 |doi=10.1080/11035893709444957}} and received its name to honor the Swedish mineralogist and artist Gregori Aminoff (1883–1947), who was an expert in the mineralogy of Långban and worked at the Swedish Museum of Natural History.
== Characteristics ==
Aminoffite is a silicate with the chemical formula Ca2(Be,Al)(Si2O7)(H2O,OH). It crystallizes in the tetragonal system.{{cite journal |last1=Huminicki |first1=D. M.C. |last2=Hawthorne |first2=F. C. |title=Refinement of the crystal structure of aminoffite |journal=The Canadian Mineralogist |date=1 June 2002 |volume=40 |issue=3 |pages=915–922 |doi=10.2113/gscanmin.40.3.915}} Its hardness on the Mohs scale is between 5.5 and 6. According to the Nickel–Strunz classification, the aminoffite belongs to "09.BH - Sorosilicates with anions Si3O10, Si4O11, etc.; cations in tetrahedral coordination and greater coordination' along with the minerals kinoite, akatoreite, and fencooperite.
Formation and deposits
Aminoffites are found as well-formed crystals in veins and cavities in massive magnetite and limonite. It is usually found associated with other minerals such as: magnetite, goethite, fluorite, calcite and baryte. It was discovered in 1937 in Långban, Filipstad of Värmland, Sweden. It has also been found in the alkaline massif in Dugdu of Tuva in Russia and Taronga of New South Wales in Australia.