# Seamanite

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> Source: https://en.wikipedia.org/wiki/Seamanite
> Source revision: 1299520783
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{{Short description|Rare manganese boron phosphate mineral}}
{{Infobox mineral
| name        = Seamanite
| category    = [Borate minerals](/source/Borate_minerals)
| boxwidth    = 280px
| boxbgcolor  = 
| image       = Seamanite-zr17a.jpg
| imagesize   = 260px
| caption     = Seamanite crystals on a rock sample<br />(5 x 4 x 3 cm)
| formula     = Mn<sub>3</sub>[B(OH)<sub>4</sub>](PO<sub>4</sub>)(OH)<sub>2</sub><ref name=mindat/>
| IMAsymbol   = Sem<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   = 372.64 g/mol<ref name=webmineral>{{cite web|title=Seamanite Mineral Data|url=https://www.webmineral.com/data/Seamanite.shtml |publisher=Webmineral |access-date=April 13, 2012}}</ref>
| strunz      = 6.AC.65<ref name=webmineral/>
| dana        = 43.4.5.1<ref name=mindat/>
| system      = [Orthorhombic](/source/Orthorhombic)
| class       = Dipyramidal (mmm) <br/>[H-M symbol](/source/H-M_symbol): (2/m 2/m 2/m)<ref name=handbook />
| symmetry    = ''Pbnm''
| unit cell   = a = 7.811&nbsp;[Å](/source/angstrom_unit), b = 15.114&nbsp;Å <br/>c = 6.691&nbsp;Å, Z&nbsp;=&nbsp;4
| color       = yellow, yellow-brown, pink<ref name=mindat>{{cite web|title=Seamanite|url=http://www.mindat.org/min-3599.html|publisher=Mindat|access-date=April 13, 2012}}</ref>
| habit       = acicular<ref name=webmineral/>
| twinning    = 
| cleavage    = distinct on {001}<ref name=handbook/>
| fracture    = brittle<ref name=webmineral/>
| tenacity    = brittle<ref name=handbook/>
| mohs        = 4<ref name=mindat/>
| luster      = vitreous<ref name=webmineral/>
| polish      = 
| refractive  = n<sub>α</sub> = 1.640, <br/>n<sub>β</sub> = 1.663,<br/> n<sub>γ</sub> = 1.665<ref name=K222/>
| opticalprop = 
| birefringence = δ = 0.025<ref name=mindat/>
| 2V          = ≈40°<ref name=K222>Kraus, p. 222</ref>
| dispersion  = weak<ref name=mindat/>
| pleochroism = 
| fluorescence= none<ref name=webmineral/>
| absorption  =
| streak      = white<ref name=webmineral/>
| gravity     = 3.08<ref name=mindat/>
| density     = 3.08–3.128 g/cm<sup>3</sup><ref name=handbook/>
| melt        = 
| fusibility  = 
| diagnostic  = 
| solubility  = in cold, dilute acids<ref name=mindat/>
| diaphaneity = transparent<ref name=handbook/>
| other       = 
| references  = <ref name=handbook>{{cite web|title=Seamanite|url=https://www.handbookofmineralogy.org/pdfs/seamanite.pdf|work=Handbook of Mineralogy|publisher=Mineral Data Publishing|access-date=April 13, 2012}}</ref>
}}
'''Seamanite''', named for discoverer [Arthur E. Seaman](/source/Arthur_E._Seaman), is a rare [manganese](/source/manganese) [boron](/source/boron) [phosphate](/source/phosphate) mineral with formula Mn<sub>3</sub>[B(OH)<sub>4</sub>](PO<sub>4</sub>)(OH)<sub>2</sub>. The yellow to pink mineral occurs as small, needle-shaped crystals. It was first discovered in 1917 from a mine in [Iron County, Michigan](/source/Iron_County%2C_Michigan), United States and identified in 1930. {{As of|2012}}, seamanite is known from four sites in Michigan and [South Australia](/source/South_Australia).

==History==
In 1917, [Arthur E. Seaman](/source/Arthur_E._Seaman) collected a mineral sample from the [Chicagon Mine](/source/Chicagon_Mine) in [Iron County, Michigan](/source/Iron_County%2C_Michigan).{{#tag:ref|Some sources list it as the Chicagoan Mine<ref name=webmineral/>|group=lower-alpha|name=mine_name}} He correctly believed it to be a new mineral species based on a qualitative analysis of its composition by F. B. Wilson. [World War I](/source/World_War_I) delayed further study of the mineral until 1929. A study in 1930 proved it to be a new mineral and named it ''seamanite'' in honor of Seaman. They cited his career as a professor of geology and mineralogy and his contributions to the field as reasons for the naming.<ref name=K220>Kraus, p. 220.</ref>

The original analysis of the mineral in 1930 suggested seamanite to be a hydrated salt.<ref name=K223_5>Kraus, p. 223–5</ref> However, in 1971, the mineral was determined to be the [coordination compound](/source/coordination_compound) Mn<sub>3</sub>[B(OH)<sub>4</sub>](PO<sub>4</sub>)(OH)<sub>2</sub>.<ref name=M60>Moore, p. 1527.</ref>

==Description==
Seamanite is a transparent, yellow to pink mineral that occurs as needle-shaped crystals.<ref name=webmineral/> Seamanite is a brittle mineral with a [mohs hardness](/source/mohs_hardness) of 4.<ref name=mindat/> It is found in the crevices of fractured [siliceous rock](/source/siliceous_rock).<ref name=K220/> The type occurrence was found in association with small crystals of [calcite](/source/calcite), thin coatings of [manganese oxide](/source/manganese_oxide),<ref name=K220/> and fibrous [sussexite](/source/sussexite).<ref name=S575>Slawson, p. 575</ref> Seamanite has also been found with [shigaite](/source/shigaite).<ref>{{cite web|title=Seamanite – Photo Gallery|url=http://www.mindat.org/gallery.php?cform_is_valid=1&min=3599&cf_pager_page=1|publisher=Mindat|access-date=April 13, 2012}}</ref>

==Distribution==
{{As of|2012}}, seamanite is known from four locations: the Cambria-Jackson Mine in [Marquette County, Michigan](/source/Marquette_County%2C_Michigan), the Chicagon Mine and the Bengal Mine in [Iron County, Michigan](/source/Iron_County%2C_Michigan), and the Iron Monarch open cut in the [Eyre Peninsula](/source/Eyre_Peninsula), South Australia.<ref name=mindat/>

The [type material](/source/Type_material_(mineralogy)) is stored at [Michigan Technological University](/source/Michigan_Technological_University) in [Houghton, Michigan](/source/Houghton%2C_Michigan), and at the [National Museum of Natural History](/source/National_Museum_of_Natural_History) in Washington, D.C. as sample 96282.<ref name=handbook/>

==Crystallography==
[[File:Structure cristalline seamanite.png|thumb|350px|Crystal structure of seamanite:<br />gray:[H](/source/Hydrogen) red:[O](/source/Oxygen) green:[B](/source/Boron) violet:[Mn](/source/Manganese) center of yellow tetrahedrons:[P](/source/Phosphorus)]]
Seamanite is formed of [acicular](/source/Acicular_(crystal_habit)) crystals elongated along [001] and showing the faces {110} and {111} up to one centimeter. It has an [orthorhombic crystal system](/source/orthorhombic_crystal_system) and the ''Pbnm'' [space group](/source/space_group). The parameters of its [unit cell](/source/unit_cell) are: a=7.811 Å, b=15.114 Å, c=6.691 Å, Z=4 units per unit cell.<ref name=handbook/>

==Notes==
{{Reflist|group=lower-alpha}}

==References==
{{Reflist}}

===Bibliography===
*{{cite journal|last1=Kraus|first1=E.H.|last2=Seaman|first2=W.A.|last3=Slawson|first3=C.B.|title=Seamanite, a new manganese phospho-borate from Iron County, Michigan|journal=[American Mineralogist](/source/American_Mineralogist)|date=June 1930|volume=15|issue=6|pages=220–225|publisher=[Mineralogical Society of America](/source/Mineralogical_Society_of_America)|url=http://www.minsocam.org/ammin/AM15/AM15_220.pdf|access-date=April 13, 2012}}
*{{cite journal|last1=Moore|first1=Paul B.|last2=Ghose|first2=Subrata|title=A Novel Face-Sharing Octahedral Trimer in the Crystal Structure of Seamanite|journal=[American Mineralogist](/source/American_Mineralogist)|publisher=Mineralogical Society of America|date=September–October 1971|volume=56|issue=9 & 10|pages=1527–1538|url=http://www.minsocam.org/ammin/am56/am56_1527.pdf|access-date=April 13, 2012}}
*Palache, P.; Berman H.; Frondel, C. (1960). "''Dana's System of Mineralogy, Volume II: Halides, Nitrates, Borates, Carbonates, Sulfates, Phosphates, Arsenates, Tungstates, Molybdates, Etc. (Seventh Edition)"'' John Wiley and Sons, Inc., New York, pp. 388–389.
*{{cite journal|last=Slawson|first=Chester B.|title=Sussexite from Iron County, Michigan|journal=[American Mineralogist](/source/American_Mineralogist)|publisher=Mineralogical Society of America|date=December 1934|volume=19|issue=12|pages=575–578|url=http://www.minsocam.org/ammin/AM19/AM19_575.pdf|access-date=April 13, 2012}}

==Further reading==
*{{cite journal|last1=Huminicki|first1=Danielle M.C.|last2=Hawthorne|first2=Frank C.|title=Hydrogen Bonding in the Crystal Structure of Seamanite|journal=The Canadian Mineralogist|year=2002|volume=40|issue=3|pages=923–928|url=https://rruff.geo.arizona.edu/doclib/cm/vol40/CM40_923.pdf|access-date=April 14, 2012|doi=10.2113/gscanmin.40.3.923}}
*{{cite journal|last1=McConnell|first1=Duncan|last2=Pondrom|first2=Walter L. Jr.|title=X-ray Crystallography of Seamanite|journal=[American Mineralogist](/source/American_Mineralogist)|publisher=Mineralogical Society of America|date=July 1941|volume=26|issue=7|pages=446–447|url=http://www.minsocam.org/ammin/AM26/AM26_446.pdf|access-date=April 13, 2012}}

==External links==
{{commonscat-inline|Seamanite}}

Category:Borate minerals
Category:Phosphate minerals
Category:Manganese(II) minerals
Category:Orthorhombic minerals
Category:Minerals in space group 62

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Adapted from the Wikipedia article [Seamanite](https://en.wikipedia.org/wiki/Seamanite) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Seamanite?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.