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Mayflower Chrome Mine (Burnham and Wilson Mine; Mayflower property; Mayflower deposit), Mountain Top, French Creek District, Calaveras Co., California, USA

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A Cr deposit/occurrence located in the NW¼, sec. 9, T1N, R13E MDM, 1.5 km (0.9 mile) ESE of Mountain Top, and about 5 miles SE of Copperopolis (about 1,300 feet NW of the Liberty Mine; a short distance SW of Bean Gulch near the center of the NW¼ of the section). Discovered and first operated in 1916. Owned & operated by C.A. Gillis, California (1941-1976). Owned by the U.S. Bureau of Land Management, Sacramento Office, California (100%) (1976). MRDS database stated accuracy for this location is 10 meters.

The ore body strikes N30W and dips 90N at a thickness of 3 meters, width of 10 meters and a length of 30 meters. It is tabular, disseminated. A second (?) ore body is lenticular. The primary mode of origin was magmatic differentiation. Primary ore control was lithology. Wallrock alteration is intense (carbonitization). Chromite lenses 1 to 4 feet thick. Most of the ore is black, massive and medium-grained chromite having a submetallic luster. Small amounts of medium grade disseminated ore are present. Considerable talc and kammererite occur with the chromite. Local rocks include ultramafic rocks, chiefly Mesozoic, unit 2 (Western Sierra Nevada and Klamath Mountains).

Workings include surface and underground openings comprised of a small shaft 15 feet deep and an open cut 45 feet long, 3 to 4 feet wide, and 40 feet deep. There is also a caved tunnel about 100 feet long.

Production was 667 long tons containing 48% Cr2O3. Reserves probably limited to a few tons.

Analytical data results: Ore shipped assayed at 48% Cr2O3.

Mineral List

7 entries listed. 2 valid minerals. 1 erroneous literature entry.

The above list 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.


Bradley, W.W., Huguenin, Emile, Logan, C.A., Tucker, W.B., and Waring, C.A. (1918), Manganese and chromium in California: California Mining Bureau. Bulletin 76, 248 pp.: 121.

Logan, Clarence August (1925), Sacramento field division: California Mining Bureau. (Report 21): 21(2): 165.

Cater, F.W., Jr. (1948b), Chromite deposits of Calaveras and Amador Counties, California: California Division Mines Bulletin 134, part III, Chapter 2: 42, 50, Pl. 5.

Taliaferro, N. L., and Solari, A. J. (1949), Geology of the Copperopolis quadrangle, California: California Division of Mines Bulletin 145: Pl. 2.

Clark, Wm. B. & P.A. Lydon (1962), Mines and mineral resources of Calaveras County, California: California Division of Mines & Geology County Report 2: 21-22, 129, Pl. D.

Murdoch, Joseph & Robert W. Webb (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 136.

Stinson, Melvin Clarence (1975) California Division of Mining and Geology Mineral Property Report (unpublished).

Pemberton, H. Earl (1983), Minerals of California; Van Nostrand Reinholt Press: 155 (map 4-6), 433.

USGS (2005), Mineral Resources Data System (MRDS): U.S. Geological Survey, Reston, Virginia, loc. file ID #10027954 & 10162552.

U.S. Bureau of Mines, Minerals Availability System (MAS) file ID #0060090562.

Map GP-561.

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