boussingaultite

{{Short description|Rare ammonium magnesium sulfate mineral}}

{{Infobox mineral

| name = Boussingaultite

| image =

| alt =

| caption =

| category = Sulfate mineral

| formula = (NH₄)₂Mg(SO₄)₂·6H₂O

| IMAsymbol=Bsg{{Cite journal|last=Warr|first=L.N.|date=2021|title=IMA–CNMNC approved mineral symbols|journal=Mineralogical Magazine|volume=85|issue=3|pages=291–320|doi=10.1180/mgm.2021.43|bibcode=2021MinM...85..291W|s2cid=235729616|doi-access=free}}

| molweight = 360.60 g/mol

| strunz = 7.CC.60

| dana = 29.03.07.02

| system = Monoclinic

| class = Prismatic (2/m)
(same H-M symbol)

| symmetry = P2₁/a

| unit cell = a = 9.324(7) Å,
b = 12.597(9) Å,
c = 6.211(5) Å; β = 1.472°; Z = 2

| color = Colorless, yellow pink, light yellow, pink; colorless in transmitted light

| colour =

| habit =

| twinning =

| cleavage = {201} perfect (synthetic)

| fracture =

| tenacity =

| mohs = 2

| luster = Vitreous (glassy), silky

| streak = White

| diaphaneity = Transparent to translucent

| gravity = 1.73

| density = {{val|1.7|ul=g/cm3}}

| polish =

| opticalprop = Biaxial (+)

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| pleochroism =

| 2V = 51°11′

| dispersion = r > v, perceptible

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| diagnostic =

| solubility = Soluble in H₂O

| impurities =

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| references = {{cite web|title=Boussingaultite Mineral Data|url=http://webmineral.com/data/Boussingaultite.shtml|publisher=Webmineral.com|accessdate=2011-10-25}}{{cite web|title=Boussingaultite mineral information and data|url=http://www.mindat.org/min-743.html|publisher=Mindat.org|accessdate=2011-10-25}}{{cite web|title=Boussingaultite|url=http://www.handbookofmineralogy.org/pdfs/boussingaultite.pdf|publisher=Mineral Data Publishing|accessdate=2011-10-25}}

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Boussingaultite is a rare ammonium magnesium hydrated sulfate mineral of the chemical formula: (NH₄)₂Mg(SO₄)₂ · 6 H₂O. The formula of boussingaultite is that of Tutton's salts type. It was originally described from geothermal fields in Tuscany, Italy, where it occurs together with its iron analogue mohrite,Fleischer M. 1965: New mineral names. American Mineralogist, 50, pp. 805 but is more commonly found on burning coal dumps.Chesnokov B. V. and Shcherbakova E. P. 1991: Mineralogiya gorelykh otvalov Chelyabinskogo ugolnogo basseina - opyt mineralogii tekhnogenesa. Nauka, Moscow The mineral possess monoclinic symmetry and forms clear, often rounded crystals.

The mineral is named after the French chemist Jean-Baptiste Boussingault (1802–1887).{{cite journal | last1 = Culka | first1 = Adam | last2 = Jehlička | first2 = Jan | last3 = Němec | first3 = Ivan | title = Raman and infrared spectroscopic study of boussingaultite and nickelboussingaultite | journal = Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy | volume = 73 | issue = 3 | pages = 420–3 | year = 2009 | pmid = 19062333 | doi = 10.1016/j.saa.2008.10.026 |bibcode = 2009AcSpA..73..420C }}