Vote for your favorite mineral in #MinCup26! - Quartz vs. Asagiite
It's a classic vs a newbie as the most common named mineral in the crust Quartz is up against an exceedingly-rare sea foam-green mineral discovered just a few years ago Asagiite.
Log InRegister
Quick Links : The Mindat ManualThe Rock H. Currier Digital LibraryMindat Newsletter [Free Download]
Home PageAbout MindatThe Mindat ManualHistory of MindatCopyright StatusWho We AreContact UsAdvertise on Mindat
Donate to MindatCorporate SponsorshipSponsor a PageSponsored PagesMindat AdvertisersAdvertise on Mindat
Learning CenterWhat is a mineral?The most common minerals on earthInformation for EducatorsMindat ArticlesThe ElementsThe Rock H. Currier Digital LibraryGeologic TimeExplore Fossils
Minerals by PropertiesMinerals by ChemistryMineral Visual ExplorerAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
Keyword(s):
 
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsUsersMineral MuseumsClubs & OrganizationsMineral Shows & EventsThe Mindat DirectoryDevice SettingsThe Mineral QuizTime Machine
Photo SearchPhoto GalleriesSearch by ColorPhoto Colour ExplorerNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryPhotography

Sillimanite from
Guy Hill pegmatite area, Jefferson County, Colorado, USA


Locality type:Area
Classification
Species:Sillimanite
Formula:Al2(SiO4)O
Confirmation
Validity:Believed Valid
Data
Mineral Data:Click here to view Sillimanite data
Locality Data:Click here to view Guy Hill pegmatite area, Jefferson County, Colorado, USA
Data Identifiers
Mindat Occurrence Record ID:430584
Long-form Identifier:1:3:430584:2
GUID (UUID V4):0
Nearest other occurrences of Sillimanite
5.2km (3.2 miles) ⓘLadwig Group (Ladwig No. 2; Ladwig No. 3; Claims: Ladwig No. 1), Ralston Buttes Mining District, Jefferson County, Colorado, USA
11.0km (6.8 miles) ⓘAjax Mica Mine (Floyd Hill Mica Mine), Clear Creek Pegmatite Province, Clear Creek County, Colorado, USA
11.3km (7.0 miles) ⓘCreswell Mine, Bergen Park area, Jefferson County, Colorado, USA
13.1km (8.1 miles) ⓘUnnamed Rutile Occurrence (MRDS - 10090176), Clear Creek Pegmatite Province, Jefferson County, Colorado, USA
14.4km (9.0 miles) ⓘVigilant; Banta Hill; Gold; Bunkhouse Occurrence, Idaho Springs Mining District (Virginia Mining District), Clear Creek County, Colorado, USA
15.5km (9.6 miles) ⓘBonanza, Central City Mining District (Central Mining District), Gilpin County, Colorado, USA
17.7km (11.0 miles) ⓘOld Town Shaft, Central City Mining District (Central Mining District), Gilpin County, Colorado, USA
18.3km (11.4 miles) ⓘJennie Lind Tunnel No. 1, Idaho Springs, Lawson Mining District, Clear Creek County, Colorado, USA
22.0km (13.7 miles) ⓘTurkey Creek, Jefferson County, Colorado, USA
26.7km (16.6 miles) ⓘMurry Mine, Lawson Mining District, Clear Creek County, Colorado, USA
References
Eckel, Edwin Butt; Cobban, Robert R.; Mosburg, Shirley K.; Foord, Eugene E. (1997) Minerals of Colorado. Fulcrum Publishing.
 
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: September 6, 2026 00:27:48
Go to top of page