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

Old Peru, Madison County, Iowa, USAi
Regional Level Types
Old PeruUnincorporated Community
Madison CountyCounty
IowaState
USACountry

This page is currently not sponsored. Click here to sponsor this page.
PhotosMapsSearch
02894050017272316985286.jpg
Selenite

Old Peru, Madison County, Iowa, USA
02894050017272316985286.jpg
Selenite

Old Peru, Madison County, Iowa, USA
02894050017272316985286.jpg
Selenite

Old Peru, Madison County, Iowa, USA
Latitude & Longitude (WGS84):
41° 14' 8'' North , 93° 56' 42'' West
Latitude & Longitude (decimal):
41.23583,-93.94523
GRN:
N28W51
Type:
Unincorporated Community
Köppen climate type:
Dfa : Hot-summer humid continental climate
Mindat Locality ID:
239239
Long-form identifier:
mindat:1:2:239239:7
GUID (UUID V4):
0
Other/historical names associated with this locality:
Peru


Old Peru is an unincorporated community. It was laid out as a town in 1855, but it declined when the railroad missed it by a mile.

Select Mineral List Type

Standard Detailed Gallery Strunz Chemical Elements

Mineral List


1 valid mineral.

Detailed Mineral List:

ⓘ Gypsum
Formula: CaSO4 · 2H2O
ⓘ Gypsum var. Selenite
Formula: CaSO4 · 2H2O

Gallery:

List of minerals arranged by Strunz 10th Edition classification

Group 7 - Sulphates, Chromates, Molybdates and Tungstates
ⓘGypsum7.CD.40CaSO4 · 2H2O
ⓘvar. Selenite7.CD.40CaSO4 · 2H2O

List of minerals for each chemical element

HHydrogen
Hⓘ GypsumCaSO4 · 2H2O
Hⓘ Gypsum var. SeleniteCaSO4 · 2H2O
OOxygen
Oⓘ GypsumCaSO4 · 2H2O
Oⓘ Gypsum var. SeleniteCaSO4 · 2H2O
SSulfur
Sⓘ GypsumCaSO4 · 2H2O
Sⓘ Gypsum var. SeleniteCaSO4 · 2H2O
CaCalcium
Caⓘ GypsumCaSO4 · 2H2O
Caⓘ Gypsum var. SeleniteCaSO4 · 2H2O

Other Databases

Wikipedia:https://en.wikipedia.org/wiki/Old_Peru,_Iowa
Wikidata ID:Q7084725
GeoNames ID:4869883

Other Regions, Features and Areas containing this locality

North AmericaContinent
North America PlateTectonic Plate

This page contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders for access and that you are aware of all safety precautions necessary.
Quick NavTopMineral ListOther DatabasesOther Regions
 
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 16:23:28 Page updated: January 24, 2026 05:38:53
Go to top of page