Help|Log In|Register|
Home PageMindat NewsThe Mindat ManualHistory of MindatCopyright StatusManagement TeamContact UsAdvertise on Mindat
Donate to MindatSponsor a PageSponsored PagesTop Available PagesMindat AdvertisersAdvertise on Mindat
Minerals by PropertiesMinerals by ChemistryAdvanced Locality SearchRandom MineralSearch 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
StatisticsThe ElementsMember ListBooks & MagazinesMineral Shows & EventsThe Mindat DirectoryHow to Link to MindatDevice Settings
Photo SearchPhoto GalleriesNew Photos TodayNew Photos YesterdayMembers' Photo GalleriesPast Photo of the Day Gallery

Blue Bird Mine (Bluebird Mine; Zilla Mine; Twin-S Mine; Cumberland Mine; Thornewood Mine; Blue Bird Silver Mining Co. property), Bunker Hill District (Copper Creek District), Galiuro Mts, Pinal Co., Arizona, USA

This page is currently not sponsored. Click here to sponsor this page.
Latitude & Longitude (WGS84): 32° 45' 47'' North , 110° 28' 14'' West
Latitude & Longitude (decimal): 32.7630555556, -110.470555556
Other regions containing this locality:Sonoran Desert, North America

A former underground Pb-Ag-Cu-Au-Zn-Mo-V-Fe mine located in the SE¼ sec. 2, T8S, R18E, 1 mile NE of Copper Creek post office, at an altitude of approximately 4,600 feet, on private land. Located in a South-sloping gulch tributary to Copper Creek. Owned by the Copper State Metals Mining Co. (1910-1914), which operated it as the renamed Cumberland Mine; then acquired by Mr. George Young who operated it in a small way (1914-1918); finally, during the period 1918-1930, it was operated successively by Blue Bird Silver Mining Co.; Twin-S Mining Co.; and the Field Mining Corp. Intermittent production continued and during 1939-1940 Blue Bird Mining Company mined it. In 1947 Bluebird Mines, Inc. reopened the mine. It closed in 1948. Also known as / designated: Unpatented claim MS 3526, Twin-S Mining Co. property; OPatented claims MS 4123 Red Bird; Fields Mining Corp. property.

The Blue Bird vein occupies a fissure zone in granodiorite. This ore zone is 213.3 meters long, 1.52 meters wide, with a depth-to-bottom of 163 meters, striking N40º to 60ºE. and dipping 80º to 85ºSE, with a plunge of 45NE. It is from 2 to 5 feet wide and consists of numerous sub-parallel fissures en echelon. In many places it has been intruded by small andesite dikes. Galena and tetrahedrite are the major ore minerals. Ore pinches and swells. There are barren areas.

Two distinct mineralized bodies occur in the vein. The main orebody, containing sulfides of Pb, Ag, Cu, and Fe, has been followed from surface to the 535 level and found to pitch 45ºNE. The other body, containing wulfenite of sub-commercial grade, apexes near the 335 level.

The main ore zone consists of sulfide-filled fractures cutting quartz, altered granodiorite, and andesite. In many places, sulfides occur along the fault which forms the footwall of the vein, but commonly stringers of galena follow fractures crossing the vein. Along single fractures the sulfide zones are an inch or less in width, but, where several of the fractures meet, widths of 3 to 9 inches (7.5 to 22.5 cm) are common. The ore pinches and swells along the individual fractures, and within the orebody are barren areas. Crushing has occurred within the vein, and these areas are barren. Towards the horizontal limits of the orebody, the amount of sulfides diminishes, although the vein continues. In general, only slight oxidation of the Fe & Cu minerals is apparent in the main vein.

The mineralized portion of the vein NE of the sulfide body on the lower levels occurs within a breccia that has been followed on the 535 level for at least 200 feet. Angular to rounded, altered blocks of granodiorite, 4 to 8 inches (10 to 20 cm) across, surrounded and cemented by quartz, limonite, and psilomelane, occur within a zone 4 to 6 feet wide. Small dikes have intruded the breccia. On the 335 and 435 levels, the breccia zone is adjacent to the sulfide body, but on the 535 level about 100 feet of fresh granodiorite separates the two bodies. A fault containing 2 to 4 inches (5 to 10 cm) of gouge, quartz, and limonite cuts the breccia zone and connects with the galena-bearing fissures of the sulfide body. The wulfenite on the 535 level occcurs with limonite, partly filling open spaces within the quartz network. Psilomelane is present as stains on quartz and as stringers generally less than ¾ inch wide, and cements brecciated blocks of granodiorite.

The copper content of these ores increases with depth. The granodiorite wall rock show partial alteration for a few feet from the vein to kaolin, sericite, and chlorite. Small grains of pyrite are disseminated in the granodiorite. Alteration of rock fragments within the vein is more intense than that within the walls.

Workings include 1 vertical shaft, 7 levels, now mostly inaccessible; 1 open stope (see Arizona Bureau of Mines Bull. 158: 64, figure 15 for plan of workings). The workings achieved a depth of 163.07 meters and a length of 1524 meters. This mine was worked intermittantly during 1914, 1918-1930, 1939-1940, 1947-1948. From 1939-1940 the mine mill concentrated capacity of 25 tons per day. In 1947-1948, a 50 ton capacity concentrator was in operation and 598 tons were treated. Production prior to 1926 estimated at $150,000, mainly Pb & Ag (period values). During 1926-39, output of Pb-Ag-Cu was approximately $350,000 (period values). 598 tons of ore mined in 1948 yielded 31,200 pounds of Pb, 2,100 pounds of Cu, 1,085 oz. Ag & 3 oz. Au, valued in all at $6,021 (period values).

Mineral List

23 valid minerals.

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.


Tenny, J.B. (1927-1929) History of Mining in Arizona, Special Cllection, University of Arizona Library & Arizona Bureau of Mines Library: 329.

Kuhn, T.H. (1938) Arizona Bureau of Mines Bull. 145: 127-130.

Kuhn (1941) Economic Geology: 36(5): 529.

Wilson, E.D. (1941).

Denton, T.C. (1947) Old Reliable Mine. U.S Bureau of Mines Report of Investigation 4006.

Galbraith, F.W. (1947), Minerals of Arizona, Arizona Bureau of Mines Bull. 153: 16, 18, 27.

Kuhn, T.H. (1951), Bunker Hill District, in Arizona zinc and lead deposits, Arizona Bureau of Mines Bull. 158: 56-65.

US Atomic Energy Commission Preliminary Reconnaissance Report 172-488 (1953): 38.

Galbraith, F.W. & D.J. Brennan (1959), Minerals of Arizona: 32, 50, 79.

Simons, F.S. (1964), Geology of the Klondyke quadrangle, Graham and Pinal Counties, Arizona, USGS PP 461.

Guthrie and Moore (1978) Arizona Geological Society Digest: 11: 25-31.

Anthony, J.W., et al (1995), Mineralogy of Arizona, 3rd. ed.: 100, 158, 201, 229, 339, 385, 393, 417, 423, 426.

U.S. Bureau of Mines War Minerals Report #275.

USGS Oak Grove Canyon Quadrangle map.

U.S. Bureau of Land Management Mining District Sheet 741.

Arizona Department of Mineral Resources Blue Bird Mine file.

MRDS database Dep. ID #10039466, MRDS ID #M050123; and Dep. ID #10103552, MRS ID #M030468; and Dep. ID #10161997, MAS ID #0040210181.

Mineral and/or Locality is an outreach project of the Hudson Institute of Mineralogy, a 501(c)(3) not-for-profit organization.
Copyright © and the Hudson Institute of Mineralogy 1993-2017, except where stated. relies on the contributions of thousands of members and supporters.
Privacy Policy - Terms & Conditions - Contact Us Current server date and time: September 24, 2017 16:44:41 Page generated: September 23, 2017 20:48:12
Go to top of page