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

Gold Bar Mine (O'Brien Mine; Little Jim; Jenny Lynn; Interior Mining and Trust Co. Mine; Homestake; Crown; Black Bear), Amazon Wash, Constellation, Black Rock District, Yavapai Co., Arizona, USA

This page is currently not sponsored. Click here to sponsor this page.
Lock Map
Latitude & Longitude (WGS84): 34° 5' 4'' North , 112° 34' 9'' West
Latitude & Longitude (decimal): 34.08445,-112.56917
GeoHash:G#: 9qpcykvsk
Locality type:Mine
Köppen climate type:BSk : Cold semi-arid (steppe) climate

‡Ref.: USGS Mineral Resources of the US (1907): Part 1: 181.

Arizona Mining Journal (1918) March, 1918: 23.

Arizona Mining Journal (1918) December, 1918: 7.

Wilson, E.D., et al (1934), Arizona Lode Gold Mines and Gold Mining. Arizona Bureau of Mines Bull. 137: 63-64.

Koschmann, A.H. and Bergendahl, M.H. (1968) Principal Gold Producing Districts of the United States. USGS PP 610: 47.

Niemuth, N.J. (1987), Arizona Mineral Development 1984-1986, Arizona Department of Mines & Mineral Resources Directory 29.

Phillips, K.A. (1987), Arizona Industrial Minerals, 2nd. Edition, Arizona Department of Mines & Minerals Mineral Report 4, 185 pp.

Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd.ed.: 206.

USGS Morgan Butte Quadrangle map.

U.S. Bureau of Land Management Mining District Sheet 259 & 260.

Arizona Department of Mineral Resources Gold Bar Mine file.

Arizona Department of Mineral Resources Jenny Lynn file.

MRDS database Dep. ID #10027623, MRDS ID #M003555; and Dep. ID #10137414, MAS ID #0040250778.

A former underground Au-Ag-Cu mine located 15 miles NE of Wickenburg & 2.7 miles NE of Constellation at about 3,400 feet of altitude (outcrop). Started 1888 by J. Mahoney. Subsequently owned by the Saginaw Lumber Co. (circa 1901- ); later, by the Interior Mining & Trust Co. (1907-1908), which mined the orebody from surface to 385 level on the incline; about 1915 the company reorganized into the Gold Bar Mining Co. Claims extend into the SE¼SE¼ of sec. 28, the W½SW¼ sec. 27, and the NW¼ of sec. 34.

Mineralization is a vein deposit principally in a medium-grained granite with some inclusions of schist. It is intruded by pegmatite, granite porphyry and basic dikes. Ore control was faulting, shearing and igneous activity - dikes. Ore concentration was oxidation at near surface. Alteration was minor to none.

The vein outcrops on the West side of O'Brien Gulch & occurs within a fissure zone that strikes N.70ºE. & dips 30ºNW. Its filling consists of coarsely-crystalline, glassy, grayish-white quartz. In places the quartz from the oxidized zone is rather cellular with cavities containing hematite & limonite. Oreshoot was a chimney that measured about 40 feet by 50 feet in cross-section at surface and plunged 30º SW.

Area structures include foliation in Precambrian schist and gneiss that trends N25E to N65E. Veins (and genetically-related [?]) dikes trend N10W to N40W and crosscut Precambrian fabric.

Workings include a vertical shaft to the 700 level (circa 1915). A 10-stamp mill was erected on the property.

Select Mineral List Type

Standard Detailed Strunz Dana Chemical Elements

Mineral List

4 valid minerals.

Detailed Mineral List:

Formula: Au
Description: Lode gold; free gold as fine to medium-coarse particles, both in quartz & with iron minerals.
Reference: Wilson, E.D., et al (1934), AZ Bur. Mines Bull. 137: 63-64.
Formula: Fe2O3
Reference: Wilson, E.D., et al (1934), AZ Bur. Mines Bull. 137: 63-64.
Formula: (Fe,O,OH,H2O)
Reference: Wilson, E.D., et al (1934), AZ Bur. Mines Bull. 137: 63-64.
Formula: KAl2(AlSi3O10)(OH)2
Description: Occurs in altered wall rocks.
Reference: Wilson, E.D., et al (1934), AZ Bur. Mines Bull. 137: 63-64.
Muscovite var: Sericite
Formula: KAl2(AlSi3O10)(OH)2
Description: Occurs in altered wall rocks.
Reference: Wilson, E.D., et al (1934), AZ Bur. Mines Bull. 137: 63-64.
Formula: FeS2
Reference: Wilson, E.D., et al (1934), AZ Bur. Mines Bull. 137: 63-64.

List of minerals arranged by Strunz 10th Edition classification

Group 1 - Elements
Group 2 - Sulphides and Sulfosalts
Group 4 - Oxides and Hydroxides
Group 9 - Silicates
var: Sericite9.EC.15KAl2(AlSi3O10)(OH)2
Unclassified Minerals, Rocks, etc.

List of minerals arranged by Dana 8th Edition classification

Metals, other than the Platinum Group
Group 2 - SULFIDES
AmBnXp, with (m+n):p = 1:2
Group 71 - PHYLLOSILICATES Sheets of Six-Membered Rings
Sheets of 6-membered rings with 2:1 layers
Unclassified Minerals, Rocks, etc.
var: Sericite

List of minerals for each chemical element

H Limonite(Fe,O,OH,H2O)
H MuscoviteKAl2(AlSi3O10)(OH)2
H Muscovite (var: Sericite)KAl2(AlSi3O10)(OH)2
O HematiteFe2O3
O Limonite(Fe,O,OH,H2O)
O MuscoviteKAl2(AlSi3O10)(OH)2
O Muscovite (var: Sericite)KAl2(AlSi3O10)(OH)2
Al MuscoviteKAl2(AlSi3O10)(OH)2
Al Muscovite (var: Sericite)KAl2(AlSi3O10)(OH)2
Si MuscoviteKAl2(AlSi3O10)(OH)2
Si Muscovite (var: Sericite)KAl2(AlSi3O10)(OH)2
S PyriteFeS2
K MuscoviteKAl2(AlSi3O10)(OH)2
K Muscovite (var: Sericite)KAl2(AlSi3O10)(OH)2
Fe HematiteFe2O3
Fe Limonite(Fe,O,OH,H2O)
Fe PyriteFeS2
Au GoldAu

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

Quaternary - Miocene
0 - 23.03 Ma

ID: 3185380
Cenozoic sedimentary rocks

Age: Cenozoic (0 - 23.03 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]

1600 - 1800 Ma

ID: 2952551
Early Proterozoic granitic rocks

Age: Statherian (1600 - 1800 Ma)

Description: Wide variety of granitic rocks, including granite, granodiorite, tonalite, quartz diorite, diorite, and gabbro. These rocks commonly are characterized by steep, northeast-striking foliation. (1600-1800 Ma)

Comments: ~ 1.6 - 1.8 Ga

Lithology: Major:{granite,granodiorite,tonalite}, Minor:{quartz diorite,diorite,gabbro}

Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052. [133]

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

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: August 19, 2019 17:52:24 Page generated: August 23, 2018 15:13:51
Go to top of page