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

Biotite from
Homa Mountain complex, Homa Bay County, Kenya


Locality type:Complex
Classification
Species:'Biotite' (not an IMA approved species)
Formula:K(Fe2+/Mg)2(Al/Fe3+/Mg/Ti)([Si/Al/Fe]2Si2O10)(OH/F)2
Age information
Maximum recorded age:12 Ma
Minimum recorded age:1.3 Ma
Sample ages:
Recorded ageGeologic TimeSampleDating method
112 to 1.3 MaCenozoic - K-Ar whole rock
Sample references:
1 -
Le Bas, M. J. (1977). Carbonatite-nephelinite volcanism: an African case history. London: Wiley.
Confirmation
Validity:Believed Valid
Data
Mineral Data:Click here to view Biotite data
Locality Data:Click here to view Homa Mountain complex, Homa Bay County, Kenya
Data Identifiers
Mindat Occurrence Record ID:1426737
Long-form Identifier:1:3:1426737:4
GUID (UUID V4):0
Nearest other occurrences of Biotite
14.0km (8.7 miles) ⓘSokolo Point Carbonatite, Wasaki Peninsula Carbonatites, Homa Bay County, Kenya
14.9km (9.3 miles) ⓘLake Simbi Crater, Homa Bay County, Kenya
17.1km (10.6 miles) ⓘWasaki Peninsula Carbonatites, Homa Bay County, Kenya
18.5km (11.5 miles) ⓘUsaki Ijolite Complex, Homa Bay County, Kenya
21.9km (13.6 miles) ⓘNorth Ruri, Ruri complex, Homa Bay County, Kenya
24.5km (15.3 miles) ⓘSouth Ruri, Ruri complex, Homa Bay County, Kenya
24.6km (15.3 miles) ⓘRuri complex, Homa Bay County, Kenya
43.9km (27.3 miles) ⓘRangwa carbonatite complex, Kisingiri Volcano, Homa Bay County, Kenya
43.9km (27.3 miles) ⓘKisingiri Volcano, Homa Bay County, Kenya
47.9km (29.8 miles) ⓘMasumbi Au-Cu Prospect, Siaya County, Kenya
References
 
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 18, 2026 20:14:42
Go to top of page