Log InRegister
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreOur ScienceMindat Newsletter [Free Download]Contact Us
Donate to MindatSponsor a PageCorporate SponsorshipSponsored Pages
Learning CenterWhat Is a Mineral?The Most Common Minerals on EarthInformation for EducatorsMindat ArticlesMindat Newsletter [Free Download]The ElementsThe Mineral Quiz
Search FormMinerals by PropertiesMinerals by ChemistryMineral Visual ExplorerAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDMinerals by CountryAlphabetical Mineral IndexAlphabetical Locality SearchMineral Association SearchList of CountriesLocalities Near MePhoto SearchSearch ArticlesSearch GlossaryThe Rock H. Currier Digital LibraryMore Search Options
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
MineralsPetrologyFossilsMeteoritesGeologic Time
Mining CompaniesStatisticsMineral MuseumsClubs & OrganizationsMineral Shows & EventsDevice SettingsTime Machine
Read DiscussionsIdentification Request
Photo SearchPhoto GalleriesSearch by ColourPhoto Colour ExplorerNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryPhotography

Amphibole Supergroup from
Somanya，Kpong and Pore Areas, Asuogyaman District, Eastern Region, Ghana


Locality type:Occurrence
Classification
Species:'Amphibole Supergroup' (not an IMA approved species)
Formula:AB2C5(T8O22)W2
Comments:Amphiboles range up to 10 modal percent with biotite and aegirine-rich pyroxene in the leucocratic nepheline gneisses, and may be as much as 55 percent in the mafic and feldspar-poor nepheline gneisses
where they occur with grandite and aegirine-augites closer to soda augite. The amphiboles are black in hand specimens and may form a lineation.

Hastingsite (as defined by Leake, 1968) and iron-rich alkaline amphibole are the only types present. The leucocratic nepheline gneisses contain amphiboles richest in Na and Fe3+. (Holm, 1971)
Confirmation
Validity:Believed Valid
Data
Mineral Data:Click here to view Amphibole Supergroup data
Locality Data:Click here to view Somanya，Kpong and Pore Areas, Asuogyaman District, Eastern Region, Ghana
Data Identifiers
Mindat Occurrence Record ID:1425442
Long-form Identifier:1:3:1425442:2
GUID (UUID V4):0
References
Allen, J. B., Charsley, T. J. (1968) Nepheline-Syenite and Phonolite. Institute of Geological Sciences, London.
Holm, R. F. (1971). Some garnets, pyroxenes, and amphiboles from nepheline gneisses in Ghana. American Mineralogist: Journal of Earth and Planetary Materials, 56(11-12), 2111-2122.
Holm, R. F. (1974). Petrology of alkalic gneiss in the Dahomeyan of Ghana. Geological Society of America Bulletin, 85(9), 1441-1448. doi.org/10.1130/0016-7606(1974)85<1441:POAGIT>2.0.CO
Kesse, G. O. (1985) The Mineral and Rock Resources of Ghana. A.A. Balkema Publishers, Rotterdam.
Woldegabriel, Giday, Aronson, James L., Walter, Robert C. (1990) Geology, geochronology, and rift basin development in the central sector of the Main Ethiopia Rift. Geological Society of America Bulletin, 102 (4) 439-458 doi:10.1130/0016-7606(1990)102<0439:ggarbd>2.3.co;2
 
and/or  
Mindat.org® is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Mindat® and mindat.org® are registered trademarks of the Hudson Institute of Mineralogy.
Copyright © mindat.org and the Hudson Institute of Mineralogy 1993-2026, except where stated. Most political location boundaries are © OpenStreetMap contributors. Mindat.org relies on the contributions of thousands of members and supporters. Founded in 2000 by Jolyon Ralph and Ida Chau.
Content on this site may not be used to train, fine-tune, or otherwise develop artificial intelligence or machine learning models without prior written permission - see our Terms & Conditions.
To cite: Ralph, J., Von Bargen, D., Martynov, P., Zhang, J., Que, X., Prabhu, A., Morrison, S. M., Li, W., Chen, W., & Ma, X. (2025). Mindat.org: The open access mineralogy database to accelerate data-intensive geoscience research. American Mineralogist, 110(6), 833–844. doi:10.2138/am-2024-9486.
Privacy Policy - Terms & Conditions - Contact Us / DMCA issues - Report a bug/vulnerability Current server date and time: October 19, 2026 12:10:35
Go to top of page