Mindat Logo
Home Page Log In Message Board The Mindat Directory
Register Search Pages Chat Now! (2 online) Mindat Auctions

Åkermanite

Big Photo

Caspar quarry, Ettringer Bellerberg Mt. (Bellberg Mt.; Bellenberg Mt.; Billenberg Mt.; Boilenberg Mt.), Bellerberg volcano, Ettringen, Mayen, Eifel Mts, Rhineland-Palatinate, Germany
© Stephan Wolfsried

Show Åkermanite Photos (3)
Formula:
Ca
 
2
Mg[Si
 
2
O
 
7
]
System:TetragonalColour:grey-green, brown, ...
Hardness:5 - 6
Name:Named after Anders Richard Åkerman, Swedish metallurgist.


Melilite Group.
Gehlenite-Åkermanite Series.

Classification of Åkermanite

IMA status:Valid - first described prior to 1959 (pre-IMA) - "Grandfathered"
Strunz 8th edition ID:8/C.02-10
Nickel-Strunz 10th (pending) edition ID:9.BB.10

9 : SILICATES (Germanates)
B : Sorosilicates
B : Si2O7 groups, without non-tetrahedral anions; cations in tetrahedral [4] and greater coordination
Dana 8th edition ID:55.4.1.1

55 : SOROSILICATES Si2O7 Groups,Generally with no Additional Anions
4 : Si2O7 Groups, Generally with No Additional Anions with cations in [8] and lower coordination
Hey's CIM Ref.:14.6.9

14 : Silicates not Containing Aluminum
6 : Silicates of Ca with alkali or Mg or both
mindat.org URL:http://www.mindat.org/min-70.html
Please feel free to link to this page.

Physical Properties of Åkermanite

Lustre:Vitreous, Resinous
Colour:grey-green, brown, colourless
Streak:white
Hardness (Mohs):5 - 6
Cleavage:Distinct/Good

Crystallography of Åkermanite

Crystal System:Tetragonal
Class (H-M):4 2m - Scalenohedral
Space Group:P4 21m
Cell Parameters:a = 7.8288(8) Å, c = 5.0052(2) Å
Ratio:a:c = 1 : 0.639
Unit Cell Volume:V 306.77 ų (Calculated from Unit Cell)
Z:2
Comment:Synthetic material

Optical Data of Åkermanite

Type:Uniaxial (+)
RI values: nω = 1.632 nε = 1.640
Maximum Birefringence:δ = 0.008

Chart shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration.
Surface Relief:Moderate

Chemical Properties of Åkermanite

Formula:
Ca
 
2
Mg[Si
 
2
O
 
7
]
Essential elements:Ca, Mg, O, Si
All elements listed in formula:Ca, Mg, O, Si

Relationship of Åkermanite to other Species

Series:Forms a series with Gehlenite (see here)
Member of Group:
Melilite:
(Ca,Na)
 
2
(Al,Mg,Fe
2+
 
)[(Al,Si)SiO
 
7
]
Melilite Group:
Related Minerals - Nickel-Strunz Grouping):

- +
9.BB.10Cebollite
Ca
 
5
Al
 
2
Si
 
3
O
 
12
(OH)
 
4
 or near
9.BB.10Gehlenite
Ca
 
2
Al[AlSiO
 
7
]
9.BB.10Gugiaite
Ca
 
2
Be[Si
 
2
O
 
7
]
9.BB.10Hardystonite
Ca
 
2
Zn[Si
 
2
O
 
7
]
9.BB.10Jeffreyite
(Ca,Na)
 
2
(Be,Al)[Si
 
2
O
 
6
(O,OH)]
9.BB.10Okayamalite
Ca
 
2
B[BSiO
 
7
]
9.BB.10IMA2008-049
(Ca,Na)
 
2
(Al,Mg,Fe
2+
 
)(Si
 
2
O
 
7
)
9.BB.15Barylite
BaBe
 
2
[Si
 
2
O
 
7
]
9.BB.15Clinobarylite
BaBe
 
2
Si
 
2
O
 
7
9.BB.20Andrémeyerite
BaFe
2+
2
[Si
 
2
O
 
7
]
Related Minerals - Hey's Index Grouping:

- +
14.6.1Combeite
Na
 
2
Ca
 
2
Si
 
3
O
 
9
14.6.2Pectolite
NaCa
 
2
[HSi
 
3
O
 
9
]
14.6.3Pectolite-M2abc
NaCa
 
2
[HSi
 
3
O
 
9
]
14.6.4Denisovite
Ca
 
2
(K,Na)Si
 
3
O
 
8
(F,OH)
 
2
14.6.5Tokkoite
K
 
2
Ca
 
4
Si
 
7
O
 
17
(O,OH,F)
 
4
14.6.6Mountainite
KNa
 
2
Ca
 
2
[Si
 
8
O
 
19
(OH)]·6H
 
2
O
14.6.7Rhodesite
KHCa
 
2
Si
 
8
O
 
19
·5H
 
2
O
14.6.8Miserite
K(Ca,Ce)
 
4
Si
 
5
O
 
13
(OH)
 
3
14.6.10Monticellite
CaMg[SiO
 
4
]
14.6.11Merwinite
Ca
 
3
Mg[SiO
 
4
]
 
2
14.6.12Diopside
CaMg[Si
 
2
O
 
6
]
14.6.13Tremolite
☐[Ca
 
2
][Mg
 
5
][(OH)
 
2
|Si
 
8
O
 
22
]

Other Names for Åkermanite

Synonyms:
OakermaniteOkermanite
Other Languages:
German:Åkermanit
Oakermanit
Okermanit
Russian:Окерманит
Spanish:Åkermanita
Oakermanita
Okermanita
Varieties:
Justite (of Hofmann-Degen)

Other Information

Health Warning:No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.

References for Åkermanite

Reference List:Christie, O.H.J. (1961) On sub-solidus relations of silicates; IV. The system åkermanite-sodium-gehlenite and gehlenite-sodium-gehlenite. Norsk Geologisk Tidsskrift: 42: 31-44.

Valley, J.W. and Essene, E.J. (1979) Vesuvianite, akermanite, monticellite and wollastonite equlibria and high X H2O/CO2 at Cascade slide, Mt Marcy Quad, Adirondack Mts. EOS: 60: 423.

Neues Jahrbuch für Mineralogie, Monatshefte (1981): 1-10.

Courtial, P., Téqui, C., and Richet, P. (2000) Thermodynamics of diopside, anorthite, pseudowollastonite, CaMgGeO4 olivine, and åkermanite up to near the melting point. Physics and Chemistry of Minerals: 27: 242-250.

Internet Links for Åkermanite

Search Engines:
  • Look for Åkermanite on Google
  • Look for Åkermanite images on Google
    • External Links:
  • Look for Åkermanite on Webmineral
  • Look for Åkermanite on Athena Mineralogy
  • Look for Åkermanite on Wikipedia
  • Look for Åkermanite on Mineralien Atlas
  • Raman and XRD data at RRUFF project
  • American Mineralogist Crystal Structure Database
  • Search for Åkermanite in the Natural History Museum (London) online catalogue
  • Åkermanite details from Handbook of Mineralogy (PDF)
    • Mineral Dealers:
  • SpiriferMinerals.com - high quality specimens
  • Buy from David K Joyce minerals
  • High-end worldwide specimens & outstanding customer service
  • Buy RARE Minerals from Rocks of Africa
  • Buy Fine Minerals from mineralsweb.com
  • Buy Minerals and Crystals from Crystalarium.com
  • Wilensky Fine Minerals
  • Edwards Minerals - Fine Specimens
  • Top quality minerals from Kristalle of California
  • Buy minerals from Mineralium.com
  • Fabre Minerals - search for Åkermanite specimens
  • Lapis Mineral Magazin
    • Jobs:
  • Mining & Geology Jobs

    • Page Sponsor

    Sponsorship:This page is currently not sponsored. Click here to sponsor this page.

    Localities for Åkermanite

    Hide Locality List
    The map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.
    (TL) indicates type locality. ? indicates mineral may be doubtful at this locality. All other localities listed without reference should be considered as uncertain and unproven until references can be found.
    Canada
     
    • Newfoundland and Labrador
      • Labrador
    		Am Min 85:1595–1605, (2000)
    • Québec
      • Laurentides
        • Deux-Montagnes RCM
          • Oka
            • Oka complex
    		Sabina (1968)
          • Saint-Joseph-du-Lac
            • Oka complex
    		Sabina (1968)
    Czech Republic
     
    • Bohemia (Böhmen; Boehmen)
      • Ústí Region
        • Duchcov (Dux)
    		Žáček V., Skála R., Chlupáčová M., Dvořák Z. 2005: Ca-Fe3+-rich, Si-undersaturated buchite from Želénky, North-Bohemian Brown Coal Basin, Czech Republic. Eur. J. Mineral., 17, 623-633
    Germany
     
    • Lower Saxony
      • Harz Mts
        • Goslar
          • Astfeld
    		No reference listed
    • Rhineland-Palatinate
      • Eifel Mts
        • Mayen
          • Ettringen
            • Bellerberg volcano
              • Ettringer Bellerberg Mt. (Bellberg Mt.; Bellenberg Mt.; Billenberg Mt.; Boilenberg Mt.)
    		[Blass, G., Graf, H.W., Neue Mineralienfunde aus der Eifel und dem Siegerland, Mineralien-Welt 10/3, 23, 1999] [A. Wittern: Mineralfundorte in Deutschland, Schweizerbart (Stuttgart), 2001]
    Iraq
     
    • Qala-Diz (Qala-Dizeh; Qala-Diza)
      • Hero
    Israel
     
    • Negev desert
    		Gross, S. (1977): The Mineralogy of the Hatrurim Formation, Israel. Geological Survey of Israel, Bulletin no. 70, 80 pp.
    Italy
     
    • Campania
      • Naples Province
        • Somma-Vesuvius Complex
    		[Lapis 1994:5 p.13-23,58]
    • Latium
      • Rome Province
        • Campagnano di Roma
          • Sacrofano
            • Sacrofano Caldera
    Japan
     
    • Honshu Island
      • Chugoku region
        • Shimane Prefecture
    		The Mineral Species of Japan (5th ed) Matsubara
    Namibia
     
    • Otjikoto (Oshikoto) Region
      • Tsumeb
    		Ettler, V., Johan, Z., Kříbek, B., Šebek, O. & Mihaljevič, M. (2009): Mineralogy and environmental stability of slags from the Tsumeb smelter, Namibia. Applied Geochemistry 24, 1-15.
    Norway
     
    • Telemark
      • Skien
    		Jamtveit B., Dahlgren S. and Austrheim H., (1997): "High-grade contact metamorphism of calcareous rocks from the Oslo Rift, Southern Norway".
    Russia
     
    • Eastern-Siberian Region
      • Krasnoyarsk Territory (Krasnoyarsk Kray; Krasnoyarskii Krai)
        • Maimecha and Kotui Rivers Basin
    		Pavel M. Kartashov data
    • Northern Region
      • Murmanskaja Oblast'
        • Kola Peninsula
    		www.koeln.netsurf.de/~w.steffens/khib.htm
    South Africa
     
    • Mpumalanga Province
      • Eastern Bushveld Complex
        • Lydenburg District
    		Minerals of South Africa
    • Northern Cape Province
      • Kalahari manganese fields
        • Hotazel
    		[Von Bezing, K. L. et al. (1991) - The Kalahari manganese field : an update, Mineralogical Record, 22 (3), 279-302]
    Sweden
     
    • Medelpad
      • Sundsvall
    		No reference listed
    UK
     
    • Scotland
      • North West Highlands (Argyllshire)
        • Ardnamurchan
    		Handbook of Mineralogy - Anthony, Bideaux, Bladh, Nichols; Mineralogical Magazine 1965 34 : 1-15.
    USA
     
    • Colorado
      • Gunnison Co.
        • White Earth District (Powderhorn District)
    		"Minerals of Colorado, updated & revised", p. 17, by Eckel, Edwin B., 1997
    • New York
      • Essex Co.
        • Keene
          • Cascade Mountain
    		EOS: 60: 423.
    • Texas
      • Culberson Co.
        • Apache Peak area
    		Rocks & Minerals: 66(3): 196-224.
    Mineral and/or Locality
    Google
     
    www.mindat.org Web
    Copyright © Jolyon Ralph and Ida Chau 1993-2009. Site Map. Locality, mineral & photograph data are the copyright of the individuals who submitted them.Further information contact the Site hosted & developed by Jolyon Ralph. Mindat.org is an online information resource dedicated to providing free mineralogical information to all. Mindat relies on the contributions of hundreds of members and supporters. If you would like to add information to improve the quality of our database, then click here to register. Current server date and time: 21st Nov 2009 18:54:16