The Felix Mine located near Azusa, Los Angeles Co. CA has been known as a source of fine fluorite specimens at least since January, 1892 (1899). In that month W. H. Adams, Jr. donated specimen number 12766 to the California State Mining Bureau. The early history of the mine does not appear to have been recorded, but since fluorite is not included in the compilation of California minerals published by Henry Hanks in May, of 1884 (HANKS, 1884), and only small white cubes of fluorite from Mount Diablo are mentioned in the June 1886 update (HANKS, 1886) the location most probably was discovered in the intervening six year interval.

The larger crystals generally show a very attractive, and almost unique, combination to octahedral and cube face development. They frequently occur as individuals and small groups on a druzy quartz matrix. The most common color is green although blue and purple crystals are also occasionally found. The only commonly associated mineral is bladed white barite. Occasional inclusions of galena, sphalerite, and chalcopyrite in the fluorite crystals attest to their former presence in the veins. Secondary minerals such as cerussite and malachite have only been found in the deepest parts of the diggings.

The mine is located along the base of the San Gabriel Mountains about a mile east of the San Gabriel River near the town of Azusa. It is on a steep, brushy hillside composed of decomposing granite. Even with considerable imagination very little evidence of the early mining can be discerned. During the 1980s and 1990s a graded fire road ran by the site and it was possible to drive to within a 100 yards of the fluorite producing area.

During that time rockhounds kept four or five pits along a set of subparallel veins active, and a local mineral dealer, developed a big trench along one vein eventual terminating it in a short adit. During the winter of 2002 flooding washed out much of the fire road and it was not repaired. Shortly after that a major housing development was initiated in the flat land below the mine and access became more difficult. Recent collecting has been largely limited to the big trench and roadcuts along the old fire road. The other veins with there corresponding pits are no longer obvious. However, although it is hard digging nice material can still be found at the site.

Minium from the Felix Mine appears to have first been mentioned in Adolf Pabst’s (PABST, 1938) updated compilation of California minerals, although he gives no reference for it. Since that time Felix fluorite crystals containing orange blobs and labeled as fluorite with minium inclusions have become highly prized and have made their way into collections thoughout the world. In the 7th edition of Dana’s “System of Mineralogy” the Felix Mine is even listed as a significant US minium location.

I am a field collector living near the Felix Mine, and having previously collected there several times, I decided about fifteen years ago that I should have a few of these prized specimens, so I went there specifically looking for orange material. In a short time I was able to find about ten samples of orange powder either included in or associated with fluorite, but then made the mistake of taking EDS spectra of them in an SEM. About half, I think including all the actual inclusions, were very fine grained cinnabar. The other half appeared to be tiny mottramite crystals in an amorphous matrix. Since then I periodically visit the mine and nearly always find some orange material that proves to be cinnabar.

I have also since then tested samples from other people, and one historical sample from the Caltech collection, and all were cinnabar. Even with considerable effort I have not been able to locate any authentic sample of minium from the Felix Mine.

In CDMG Bulletin 189 (MURDOCH and WEBB, 1966) the reference for minium from the Felix Mine is listed as (p. c. Clarke) and it is admitted that at that time nothing else was known about Clarke, not even his or her initials, let alone how he or she supposedly initially identified the minium. In the last published update of “Minerals of California” (PEMBERTON, 1983) minium is again listed from the Felix Mine, but this time with the reference (H. E. Pemberton, pers. comm., 1970). It seems highly likely that this just means that he found the expected orange powdery material there, not that he confirmed its identity.

Based on the above I suggest that:

1. We remove minium from the mineral list for the Felix Mine,
2. People with Felix Mine samples labeled minium should change their labels,
3. Anyone reluctant to change the label should submit their material for testing.

I want to thank Stan Walker for calling the Adams donation and the early California mineral lists to my attention, and Steve Shailer for providing me the specimen with sphalerite inclusions.

(1899) Catalogue of the State Museum of California, Vol. 5. California State Mining Bureau.
Hanks H. G. (1884) Fourth Report of the State Mineralogist. California Mining Bureau Reports 4, 410.
Hanks H. G. (1886) Sixth Report of the State Mineralogist. California Mining bureau Reports 6, 145.
Murdoch J. and Webb R. W. (1966) Minerals of California. California Division of Mines and Geology Bulletin 189, 559.
Pabst A. (1938) Minerals of California. California Division of Mines Bulletin 113, 344.
Pemberton H. E. (1983) Minerals of California. Van Nostrand Reinhold Company.

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