Vote for your favorite mineral in #MinCup26! - Sphalerite vs. Anorthite
Both zinc ore Sphalerite and calcium plagioclase feldspar Anorthite have perfect cleavage that will split cleanly if you hit them with a hammer, but only one can claim a larger split of your votes!
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

Siderite from
Cotopaxi Mine (Cotopaxi lode; Gumaer Mine; Fannie lode; Fannie Mill), Mine Gulch, Cotopaxi, Cotopaxi Mining District, Fremont County, Colorado, USA


Locality type:Mine
Classification
Species:Siderite
Formula:FeCO3
Confirmation
Validity:Believed Valid
Data
Mineral Data:Click here to view Siderite data
Locality Data:Click here to view Cotopaxi Mine (Cotopaxi lode; Gumaer Mine; Fannie lode; Fannie Mill), Mine Gulch, Cotopaxi, Cotopaxi Mining District, Fremont County, Colorado, USA
Data Identifiers
Mindat Occurrence Record ID:34976
Long-form Identifier:1:3:34976:9
GUID (UUID V4):0
Nearest other occurrences of Siderite
14.0km (8.7 miles) ⓘRoad Gulch, Fremont County, Colorado, USA
14.4km (9.0 miles) ⓘHomestake No. 2 Claim (Homestake No. 6; Homestake Claims), Fremont County, Colorado, USA
14.5km (9.0 miles) ⓘDreamers Hope Claim, Fremont County, Colorado, USA
19.4km (12.0 miles) ⓘYellow Pine Barite Vein Occurrence, Waugh Mountain Area, Fremont County, Colorado, USA
21.9km (13.6 miles) ⓘOrient Iron Mine (Caesar; MS 11400; Valley View; MS 8940; Vivia B.; MS 4988; Runaway; MS 1539; Prospector; MS 1505; Villa Grove), Orient Mining District, Saguache County, Colorado, USA
29.0km (18.0 miles) ⓘTitusville and Westfall Gulch Prospects (Grape Claims No. 2 1-19 1977; Unpatented Claims: Arbor Claims No. 1-9), Westfall Gulch, Fremont County, Colorado, USA
30.3km (18.8 miles) ⓘBlack Beauty Deposit (Crater Deposit), Cleora Mining District, Chaffee County, Colorado, USA
30.6km (19.0 miles) ⓘBear Claims Nos. 1 and 2 1977 (Old Cunac Property; Wagner-Grape Creek Lode), East Pierce Gulch Area, Fremont County, Colorado, USA
32.1km (19.9 miles) ⓘBull-Domingo Mine, Silver Cliff Mining District, Custer County, Colorado, USA
33.4km (20.7 miles) ⓘPennie Poker Occurrence (Penny Poker), McKinley Mountain Area, Custer County, Colorado, USA
References
Am Min 50:1179-1212
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 3, 2026 15:17:57
Go to top of page