SUPPORT US. If is important to you, click here to donate to our Fall 2019 fundraiser!
Log InRegister
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 ElementsBooks & Magazines
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralRandom LocalitySearch by minIDLocalities Near MeSearch ArticlesSearch GlossaryMore Search Options
Search For:
Mineral Name:
Locality Name:
The Mindat ManualAdd a New PhotoRate PhotosLocality Edit ReportCoordinate Completion ReportAdd Glossary Item
Mining CompaniesStatisticsUsersMineral MuseumsMineral Shows & EventsThe Mindat DirectoryDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day GalleryMineral Photography

Millotingo Mine (San Juan Mine; San Juan de Millotingo Mine), Pacococha, Huarochiri Province, Lima Department, Peru

This page is currently not sponsored. Click here to sponsor this page.
Lock Map
Latitude & Longitude (WGS84): 11° 49' 23'' South , 76° 14' 0'' West
Latitude & Longitude (decimal): -11.82306,-76.23333
GeoHash:G#: 6mcu9r8td
Locality type:Mine
Köppen climate type:ET : Tundra

The mine is several km SE of the town of San Mateo. An access road that parallels Hwy 120 but is in a different canyon leads to the mine. Mine outbuildings are located at Lat. -11.8231, Long. -76.2333 at an elevation of 4207 m.

Millotingo Mine opened in 1933, and was originally called the San Juan Mine, or San Juan de Millotingo Mine. It was closed in 1992 because of weak metal prices and local terrorist activity by Shining Path. From 1962 until 1990 a total of 2.6 million tonnes of mill feed was produced, at an average grade of 14.5 troy ounces of silver per short ton, with gold produced as a by product, plus minor copper, lead, and zinc. The ore yielded 39 million ounces of silver and 90,000 ounces of gold over that time span. Upon closure, the mine was estimated to have 661,000 tonnes of ore remaining.

Mining at Millotingo exploited fractures in andesite where silver minerals, mainly sulphosalts, are concentrated in upper portions away from silicified zones. Lead and zinc increase with depth. The sulphosalts precipitated at a temperature near 200 C, and best silver/gold ores are shallower than 400 m.

Select Mineral List Type

Standard Detailed Strunz Dana Chemical Elements

Mineral List

8 valid minerals.

Detailed Mineral List:

Formula: CuFeS2
Reference: Norman King
Formula: [(Ag,Cu)6(Sb,As)2S7][Ag9CuS4]
Reference: Georges FAVREAU collection
Formula: Ag3SbS3
Reference: Norman King
Formula: FeS2
Reference: Norman King
Formula: Fe7S8
Reference: Norman King
Formula: SiO2
Reference: Norman King
Formula: Mn2+SiO3
Reference: Georges FAVREAU collection
Formula: ZnS
Reference: Norman King

List of minerals arranged by Strunz 10th Edition classification

Group 2 - Sulphides and Sulfosalts
Group 4 - Oxides and Hydroxides
Group 9 - Silicates

List of minerals arranged by Dana 8th Edition classification

Group 2 - SULFIDES
AmXp, with m:p = 1:1
AmBnXp, with (m+n):p = 1:1
AmBnXp, with (m+n):p = 1:2
ø > 4
ø = 3
Group 65 - INOSILICATES Single-Width,Unbranched Chains,(W=1)
Single-Width Unbranched Chains, W=1 with chains P=5
Group 75 - TECTOSILICATES Si Tetrahedral Frameworks
Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si

List of minerals for each chemical element

O QuartzSiO2
O RhodoniteMn2+SiO3
Si QuartzSiO2
Si RhodoniteMn2+SiO3
S ChalcopyriteCuFeS2
S Polybasite[(Ag,Cu)6(Sb,As)2S7][Ag9CuS4]
S PyrargyriteAg3SbS3
S PyriteFeS2
S PyrrhotiteFe7S8
S SphaleriteZnS
Mn RhodoniteMn2+SiO3
Fe ChalcopyriteCuFeS2
Fe PyriteFeS2
Fe PyrrhotiteFe7S8
Cu ChalcopyriteCuFeS2
Cu Polybasite[(Ag,Cu)6(Sb,As)2S7][Ag9CuS4]
Zn SphaleriteZnS
As Polybasite[(Ag,Cu)6(Sb,As)2S7][Ag9CuS4]
Ag Polybasite[(Ag,Cu)6(Sb,As)2S7][Ag9CuS4]
Ag PyrargyriteAg3SbS3
Sb Polybasite[(Ag,Cu)6(Sb,As)2S7][Ag9CuS4]
Sb PyrargyriteAg3SbS3

Regional Geology

This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.

Click on geological units on the map for more information. Click here to view full-screen map on

23.03 - 66 Ma

ID: 3191170
Cenozoic sedimentary rocks

Age: Paleogene (23.03 - 66 Ma)

Lithology: Sedimentary rocks

Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. [154]

Data and map coding provided by, used under Creative Commons Attribution 4.0 License


Sort by

Year (asc) Year (desc) Author (A-Z) Author (Z-A)
Cavanagh, J. and Glover, M. (1991) Mines and Miners in Peru/Las Minas del Perú. Top Publications S.A.C. [publication date may actually be 1990]
Waszkis, H. (1993) Mining in the Americas. Woodland Publ. Ltd., p. 97-98. (excerpt online at "Millotingo Mine, Peru")

External Links - thesis on silver deposits at Millotingo Mine - independent report on gold prospects in Pacococha District

This page contains all mineral locality references listed on 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 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.
Mineral and/or Locality is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization. Public Relations by Blytheweigh.
Copyright © and the Hudson Institute of Mineralogy 1993-2019, except where stated. Most political location boundaries are © OpenStreetMap contributors. relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: October 20, 2019 14:53:06 Page generated: September 30, 2018 15:57:18
Go to top of page