Hydroboracite

{{Infobox mineral | name = Hydroboracite | boxwidth = | boxbgcolor = | image = Hydroboracite-471230.jpg | imagesize = 260px | alt = | caption = | category = Inoborates | formula = CaMgB₆O₈(OH)₆·3H₂O | IMAsymbol = Hbo<ref>{{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}}</ref> | molweight = | strunz = 6.CB.15 | dana = | system = Monoclinic | class = Prismatic (2/m) <br/><small>(same H-M symbol)</small> | symmetry = ''P2/c'' | unit cell = a = 11.76, b = 6.68 <br/>c = 8.23&nbsp;[Å]; β = 102.59°; Z&nbsp;=&nbsp;2 | colour = Colourless, white | color = | habit = | twinning = | cleavage = | fracture = | tenacity = | mohs = 2 | luster = Vitreous, silky | streak = | diaphaneity = Transparent | gravity = | density = | polish = | opticalprop = Biaxial (+) | refractive = n_α = 1.520 – 1.523 n_β = 1.534 – 1.535 n_γ = 1.569 – 1.571 | birefringence = δ = 0.049 | pleochroism = | 2V = Measured: 60° to 66°, calculated: 62° to 66° | dispersion = Relatively weak | extinction = | length fast/slow = | fluorescence = | absorption = | melt = | fusibility = | diagnostic = | solubility = Very poorly soluble in cold water. Partially dissolved by prolonged submersion in boiling water. | impurities = | alteration = | other = | prop1 = | prop1text = | references = <ref>[http://webmineral.com/data/Hydroboracite.shtml Webmineral data]</ref><ref>[http://www.mindat.org/min-1967.html Mindat]</ref> }}

'''Hydroboracite''' is a hydrated borate mineral (hence the name) of calcium and magnesium, whose chemical composition is CaMgB₆O₈(OH)₆·3H₂O. It was discovered in 1834 in the Inder lake, Atyrau Province, Kazakhstan. Hydroboracite is a minor borate ore mineral.

== References == {{Reflist}}

{{mineral-stub}}

Category:Inoborates Category:Monoclinic minerals Category:Minerals in space group 13