Alma Mine, Leona Heights deposit, Leona Heights, Oakland, Oakland Hills (San Leandro Hills), Alameda County, California, USAi
| Regional Level Types | |
|---|---|
| Alma Mine | Mine |
| Leona Heights deposit | Deposit |
| Leona Heights | - not defined - |
| Oakland | - not defined - |
| Oakland Hills (San Leandro Hills) | Group of Hills |
| Alameda County | County |
| California | State |
| USA | Country |
This page is currently not sponsored. Click here to sponsor this page.
Latitude & Longitude (WGS84):
37° North , 122° West (est.)
Estimate based on other nearby localities or region boundaries.
Margin of Error:
~2km
Type:
Köppen climate type:
Mindat Locality ID:
3427
Long-form identifier:
mindat:1:2:3427:5
GUID (UUID V4):
3420c2df-7397-4752-af65-10c6281531bf
Other/historical names associated with this locality:
Alma Pyrite Mine
A S-pyrite-Cu-Ag occurrence/mine located in sec. 34, T1S, R3W, MDM, 0.5 km (0.3 mile) NE of Leona Heights proper and 8.5 km (5.3 miles) E of Oakland center, on private land. Discovered prior to 1892. Owned by Leota C. Reed (1950). MRDS database accuracy for this location is not stated. This mine was originally opened in 1892 and produced principally sulfuric acid until 1934. No pyrite was mined after 1934.
Mineralization is hosted in Pliocene rhyolite. The ore body is lenticular at a thickness of 5.49 meters. Controls for ore emplacement included fractures. The geology is similar to that of the Leona Heights Mine on the same ore zone. The pyrite contains some chalcopyrite and some secondary Cu minerals, boothite, chalcanthite and pisanite. Local rocks include Tertiary intrusive rocks (hypabyssal), unit 9 (Jurassic gabbros along Hayward Fault) and/or ultramafic rocks, chiefly Mesozoic, unit 3 (Coast Ranges and Western Klamath Mountains).
Local geologic structures include the Hayward Fault and 2 parallel, smaller faults with horizontal displacement.
Workings include underground openings with a length of 1,524 meters and was developed by 5,000 feet of tunnels and drifts. The old workings were burned and a new adit was driven at a lower level.
Copper was produced from the residue after the extraction of the acid and from leaching the dump, amounted to 375,000 pounds of Cu (1929-1935). Later, some small production was realized in 1942 & 1944. Some Ag and a little Au were also produced as by-products. The figure for Cu production includes that from the nearby Leona Mine.
Analytical data results: 1% Cu.
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsCommodity List
This is a list of exploitable or exploited mineral commodities recorded at this locality.Mineral List
15 valid minerals. 1 (TL) - type locality of valid minerals.
Detailed Mineral List:
| ⓘ Alunogen Formula: Al2(SO4)3 · 17H2O Colour: White Description: Pulverulent material. References: |
| ⓘ Boothite (TL) Formula: CuSO4 · 7H2O Type Locality: References: |
| ⓘ Chalcanthite Formula: CuSO4 · 5H2O Description: Abundant as massive coatings and crystals. References: |
| ⓘ Chalcopyrite Formula: CuFeS2 Description: Occurs in small amounts in massive pyrite. |
| ⓘ Copiapite Formula: Fe2+Fe3+4(SO4)6(OH)2 · 20H2O Habit: Acicular Colour: Yellow Description: Needles. |
| ⓘ Copper Formula: Cu Description: Occurs as fine arborescent groups of crystals. References: |
| ⓘ Epsomite Formula: MgSO4 · 7H2O Description: Occurs as efflorescences on walls. References: |
| ⓘ Halotrichite Formula: FeAl2(SO4)4 · 22H2O |
| ⓘ Hematite Formula: Fe2O3 |
| ⓘ Hexahydrite Formula: MgSO4 · 6H2O |
| ⓘ Kröhnkite Formula: Na2Cu(SO4)2 · 2H2O References: |
| ⓘ 'Limonite' |
| ⓘ Melanterite Formula: Fe2+(H2O)6SO4 · H2O Description: Occurs on mine walls (post-mining product). References: |
| ⓘ Melanterite var. Copper-bearing Melanterite Formula: (Fe,Cu)SO4 · 7H2O Description: A secondary mineral (post-mining) forming on mine walls. References: |
| ⓘ Pentahydrite Formula: MgSO4 · 5H2O References: |
| ⓘ Pyrite Formula: FeS2 References: |
| ⓘ Römerite Formula: Fe2+Fe3+2(SO4)4 · 14H2O |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 1 - Elements | |||
|---|---|---|---|
| ⓘ | Copper | 1.AA.05 | Cu |
| Group 2 - Sulphides and Sulfosalts | |||
| ⓘ | Chalcopyrite | 2.CB.10a | CuFeS2 |
| ⓘ | Pyrite | 2.EB.05a | FeS2 |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | Hematite | 4.CB.05 | Fe2O3 |
| Group 7 - Sulphates, Chromates, Molybdates and Tungstates | |||
| ⓘ | Chalcanthite | 7.CB.20 | CuSO4 · 5H2O |
| ⓘ | Pentahydrite | 7.CB.20 | MgSO4 · 5H2O |
| ⓘ | Hexahydrite | 7.CB.25 | MgSO4 · 6H2O |
| ⓘ | Melanterite | 7.CB.35 | Fe2+(H2O)6SO4 · H2O |
| ⓘ | var. Copper-bearing Melanterite | 7.CB.35 | (Fe,Cu)SO4 · 7H2O |
| ⓘ | Boothite (TL) | 7.CB.35 | CuSO4 · 7H2O |
| ⓘ | Epsomite | 7.CB.40 | MgSO4 · 7H2O |
| ⓘ | Alunogen | 7.CB.45 | Al2(SO4)3 · 17H2O |
| ⓘ | Römerite | 7.CB.75 | Fe2+Fe3+2(SO4)4 · 14H2O |
| ⓘ | Halotrichite | 7.CB.85 | FeAl2(SO4)4 · 22H2O |
| ⓘ | Kröhnkite | 7.CC.30 | Na2Cu(SO4)2 · 2H2O |
| ⓘ | Copiapite | 7.DB.35 | Fe2+Fe3+4(SO4)6(OH)2 · 20H2O |
| Unclassified | |||
| ⓘ | 'Limonite' | - | |
List of minerals for each chemical element
| H | Hydrogen | |
|---|---|---|
| H | ⓘ Alunogen | Al2(SO4)3 · 17H2O |
| H | ⓘ Boothite | CuSO4 · 7H2O |
| H | ⓘ Chalcanthite | CuSO4 · 5H2O |
| H | ⓘ Copiapite | Fe2+Fe43+(SO4)6(OH)2 · 20H2O |
| H | ⓘ Epsomite | MgSO4 · 7H2O |
| H | ⓘ Halotrichite | FeAl2(SO4)4 · 22H2O |
| H | ⓘ Hexahydrite | MgSO4 · 6H2O |
| H | ⓘ Kröhnkite | Na2Cu(SO4)2 · 2H2O |
| H | ⓘ Melanterite | Fe2+(H2O)6SO4 · H2O |
| H | ⓘ Pentahydrite | MgSO4 · 5H2O |
| H | ⓘ Römerite | Fe2+Fe23+(SO4)4 · 14H2O |
| H | ⓘ Melanterite var. Copper-bearing Melanterite | (Fe,Cu)SO4 · 7H2O |
| O | Oxygen | |
| O | ⓘ Alunogen | Al2(SO4)3 · 17H2O |
| O | ⓘ Boothite | CuSO4 · 7H2O |
| O | ⓘ Chalcanthite | CuSO4 · 5H2O |
| O | ⓘ Copiapite | Fe2+Fe43+(SO4)6(OH)2 · 20H2O |
| O | ⓘ Epsomite | MgSO4 · 7H2O |
| O | ⓘ Halotrichite | FeAl2(SO4)4 · 22H2O |
| O | ⓘ Hematite | Fe2O3 |
| O | ⓘ Hexahydrite | MgSO4 · 6H2O |
| O | ⓘ Kröhnkite | Na2Cu(SO4)2 · 2H2O |
| O | ⓘ Melanterite | Fe2+(H2O)6SO4 · H2O |
| O | ⓘ Pentahydrite | MgSO4 · 5H2O |
| O | ⓘ Römerite | Fe2+Fe23+(SO4)4 · 14H2O |
| O | ⓘ Melanterite var. Copper-bearing Melanterite | (Fe,Cu)SO4 · 7H2O |
| Na | Sodium | |
| Na | ⓘ Kröhnkite | Na2Cu(SO4)2 · 2H2O |
| Mg | Magnesium | |
| Mg | ⓘ Epsomite | MgSO4 · 7H2O |
| Mg | ⓘ Hexahydrite | MgSO4 · 6H2O |
| Mg | ⓘ Pentahydrite | MgSO4 · 5H2O |
| Al | Aluminium | |
| Al | ⓘ Alunogen | Al2(SO4)3 · 17H2O |
| Al | ⓘ Halotrichite | FeAl2(SO4)4 · 22H2O |
| S | Sulfur | |
| S | ⓘ Alunogen | Al2(SO4)3 · 17H2O |
| S | ⓘ Boothite | CuSO4 · 7H2O |
| S | ⓘ Chalcopyrite | CuFeS2 |
| S | ⓘ Chalcanthite | CuSO4 · 5H2O |
| S | ⓘ Copiapite | Fe2+Fe43+(SO4)6(OH)2 · 20H2O |
| S | ⓘ Epsomite | MgSO4 · 7H2O |
| S | ⓘ Halotrichite | FeAl2(SO4)4 · 22H2O |
| S | ⓘ Hexahydrite | MgSO4 · 6H2O |
| S | ⓘ Kröhnkite | Na2Cu(SO4)2 · 2H2O |
| S | ⓘ Melanterite | Fe2+(H2O)6SO4 · H2O |
| S | ⓘ Pentahydrite | MgSO4 · 5H2O |
| S | ⓘ Pyrite | FeS2 |
| S | ⓘ Römerite | Fe2+Fe23+(SO4)4 · 14H2O |
| S | ⓘ Melanterite var. Copper-bearing Melanterite | (Fe,Cu)SO4 · 7H2O |
| Fe | Iron | |
| Fe | ⓘ Chalcopyrite | CuFeS2 |
| Fe | ⓘ Copiapite | Fe2+Fe43+(SO4)6(OH)2 · 20H2O |
| Fe | ⓘ Halotrichite | FeAl2(SO4)4 · 22H2O |
| Fe | ⓘ Hematite | Fe2O3 |
| Fe | ⓘ Melanterite | Fe2+(H2O)6SO4 · H2O |
| Fe | ⓘ Pyrite | FeS2 |
| Fe | ⓘ Römerite | Fe2+Fe23+(SO4)4 · 14H2O |
| Fe | ⓘ Melanterite var. Copper-bearing Melanterite | (Fe,Cu)SO4 · 7H2O |
| Cu | Copper | |
| Cu | ⓘ Boothite | CuSO4 · 7H2O |
| Cu | ⓘ Chalcopyrite | CuFeS2 |
| Cu | ⓘ Chalcanthite | CuSO4 · 5H2O |
| Cu | ⓘ Copper | Cu |
| Cu | ⓘ Kröhnkite | Na2Cu(SO4)2 · 2H2O |
| Cu | ⓘ Melanterite var. Copper-bearing Melanterite | (Fe,Cu)SO4 · 7H2O |
Other Databases
| Link to USGS MRDS: | 10027996 |
|---|
Other Regions, Features and Areas containing this locality
North America
- Coast MountainsMountain Range
North America PlateTectonic Plate
- Franciscan DomainDomain
- Sonoma-Livermore BasinBasin
USA
- California
- Diablo RangeMountain Range
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.
References
Larsen, Esper S. (1921) The microscopic determination of the nonopaque minerals. Bulletin Vol. 679. US Geological Survey doi:10.3133/b679 p.61
Alma Mine, Leona Heights deposit, Leona Heights, Oakland, Oakland Hills, Alameda County, California, USA