Mindat Logo

Mack Mine (John Mac mine; Mac mine; San Luis Rey claim), Rincon Mountain, Rincon, Rincon District, San Diego Co., California, USA

Photo: 2002 SDMC
Latitude: 33°16'16"N
Longitude: 116°56'35"W
On the beryl-rimmed rebecs of Ruby
Brought fresh from the hyaline streams,
She played on the banks of the Yuba
Such songs as she heard in her dreams.
—Thomas Holley Chivers (1807–1858), Lily Adair

Summary:
The Mack mine is located in the SW4SW4 Sec. 25, T10S, R1W, SBM. The main workings are situated low on a hill slope east of the San Luis Rey River Valley, approximately 1.5 miles (2.4 km) south-southeast of Rincon, at an elevation of approximately 925' AMSL. The deposit was first described as 5 to 6 feet wide pegmatite dike with granite footwall and diorite hanging wall. The chief product was gem quality beryl of various colors, some of it deep blue. Small blue crystals of spinel which may be gahnite have also been reported.

Workings & Production:
The deposit was one of the earliest sources of gem quality beryl in San Diego County, and was discovered in November of 1903 by John M. Mack[1] and local Indian J. Calac[2]. Mack and Calac worked the deposit for several years, but would not disclose the exact quantity of production, or provide detailed information regarding the number of specimens or cut stones sold.

In 1905, George Kunz reported several pounds of opaque deep blue beryl extracted, as well as several fine gem beryls, found in several colors including yellow, green, and deep blue. Kunz reported that many fine gems were cut from the clear crystals, with clouded ones cut as cabochons that displayed a pleasing cat's-eye effect. The mine was developed by 3 open cuts, the largest measuring 61 feet long, 32 feet wide, and 16 feet deep. The mine workings were located on both walls of a small arroyo, a few hundred feet northwest of the ranch house. By 1951, these workings were reported as slightly caved and overgrown with chaparral, while the dumps in the arroyo bottom had been mostly removed by flash floods.

The Mack pegmatite dike strikes north 15 degrees west, and dips about 40 degrees southwest. The vein is exposed continuously along strike for about 170 feet, and discontinuously to the south-southwest for 120 feet. The dike is about 2 feet thick for most of its length, and its maximum thickness is 3.25 feet. The pocket pegmatite comprises the lower 4 to 6 inches of the quartz-perthite pegmatite core, and the upper 6 inches of the underlying line rock.

The core zone contains numerous vugs which are lined with euhedral crystals of muscovite, albite, quartz, beryl, and garnet. The beryl crystals are greenish blue to blue, and measure up to 13mm in diameter.

By 1951, the Mack mine and the Calac ranch were reported to be privately owned by Charles W. Hall of Valley Center. Around this time, Frederick J. Rynerson reported that the "John Mac Mine" had produced more beryls than any other pegmatite mines in the region that he knew of, taking into considering the amount of work done developing the deposit.

Footnotes:
1.Macedonio Llora Merrion Machado, "Mac" (1857-1942), was born on the old Machado family homestead in Los Angeles County. Mac attended Santa Clara College and Heald's Business College in Los Angeles, and moved to Temecula in 1887 where he worked as clerk in the old government store in charge of Louis Wolf. Around 1889, he became owner of Machado & Co., a general store located downtown along the main street. In addition to his mercantile business, Mac had real-estate and mineral interests. Mac owned four hundred acres of land, and interest in twenty-five hundred acres of farming land within Riverside County. He also owned large interests in the tourmaline and beryl mines at Rincon and Smith mountain (Aguanga). Mac also owned a then-famous granite quarry near Temecula, where slabs of beautiful gray granite were cut and hauled by wagon or shipped by way of rail to their destination. While living out his life in Temecula, he also served two terms as chief ranger, four years as deputy assessor, a year as game warden, and one and a half years as postmaster. Although his surname was Machado, most people only knew him as "Mac". It is likely he occasionally used the informal English name of "John" for reasons of Spanish anonymity, and Anglo-Saxon congruence, which was common practice during the early 20th Century.
2.Also known as Feliz Calac. According to J. B. Hanley, an agreement was made between John Mack and Feliz Calac, to mine for gemstones occurring on Calac's ranch, which was described in 1958 by F. H. Weber as patented ranch land.

Mineral List

Albite
'Almandine-Spessartine Series'
Beryl
var: Aquamarine
var: Heliodor
var: Morganite
Biotite
'Clay'
Columbite
Fluorapatite
Gahnite ?
Muscovite
Orthoclase
'Perthite'
Quartz
var: Smoky Quartz
Schorl
Spinel
Spinel
var: Pleonaste

Topaz
'Tourmaline'


21 entries listed. 10 valid minerals.

The above list 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

Kunz, G. F. (1905a) Gems, jeweler's materials, and ornamental stones of California. California State Mining Bureau bulletin 37: 48, 50, 137-139.

Eakle, Arthur Starr (1906), Notes on lawsonite, columbite, beryl, barite, and calcite: University of California, Department of Geological Science Bulletin: 89.

Guinn, J. M. (1907), A History of California: Historical and Biographical Record: Macedonia Llora Merrion Machado. Historic Record Company, Los Angeles, California: 1: 1027.

Rogers, Austin Flint (1910b), Minerals from the pegmatite veins of Rincon, San Diego County, California: Columbia Univ., School of Mines Quart.: 31: 209, 212, 214, 217.

Merrill, F. J. H. (1914), Geology and Mineral Resources of San Diego and Imperial Counties: Gems, Lithia Minerals. California State Mining Bureau, San Francisco, Cal. California State Printing Office, December. Chapter 1, pages 61-110.

Hanley, J. B. (1951) Economic Geology of the Rincon Pegmatites, San Diego County, California. Department of Natural Resources, California Division of Mines, Special Report 7B: 14, 17, 18, 15-23 illus., maps.

Weber, F. H. (1963), Mines and mineral resources of San Diego County, California. California Division of Mines and Geology, County Report 3: 106, illus., maps.

Murdoch, Joseph & Webb, Robert W. (1966), Minerals of California, Centennial Volume (1866-1966): California Division Mines & Geology Bulletin 189: 79, 103, 155, 275, 346.

Rynerson, F. J. (1967), Exploring and mining for Gems and Gold in the West. Happy Camp, California: Naturegraph Publishers, Inc.: 198.

Pemberton, H. Earl (1983), Minerals of California: 148, 177, 317, 426, 447.

Fisher, J. (2002), Gem and rare-element pegmatites of southern California. Mineralogical Record: 33: 389-390.

Driggs, T. A. (2003), The Old Spanish California Machado family; Macedonia Llora Merrion Machado "Mac" and Dora Alice Vaughn "Allie".

Fisher, Jesse (2011), Mines and Minerals of the Southern California Pegmatite Province. Rocks & Minerals: 86: 14-34.

This page is currently not sponsored. To sponsor this page click here.


Mineral and/or Locality
Search Google
 
Copyright © Jolyon Ralph and Ida Chau 1993-2013. Site Map. Locality, mineral & photograph data are the copyright of the individuals who submitted them. Further information contact the Site hosted & developed by Jolyon Ralph. Mindat.org is an online information resource dedicated to providing free mineralogical information to all. Mindat relies on the contributions of hundreds of members and supporters. Mindat does not offer minerals for sale. If you would like to add information to improve the quality of our database, then click here to register.
Current server date and time: 18th Feb 2013 15:03:06
Mineral and Locality Search
Mineral:
and/or Locality:
Options
Fade toolbar when not in focusFix toolbar to bottom of page
Hide Social Media Links
Slideshow frame delay seconds