The Blue Bell Claims 1984

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The

BLUE BELL CLAIMS San Bernardino County, California

THE BLUE BELL CLAIMS San Bernardino County, California

by Millard F. Maynard, Editor

Al Valenti

John and Fern Jenkins Bob and Sugar White

Don and Jean Hall Mac and Elyga Mansfield

San Bernardino County Museum Department of Earth Sciences 2024 Orange Tree Lane Redlands, California 92373

January 1984

TABLE OF CONTENTS

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2

...................................

4

............................

6

....................................

10

History

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19

Geology

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24

.....................................

26

...............................

28

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31

Paragenesis

....................................

55

References

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60

Preface

Introduction

Location and Access Descripti on

Minera logy

List of Minerals

Description of Minerals

-2

PREF/I.CE This report has been prepared by San Bernardino County Museum volunteers.

It is one of a series we plan to prepare on

the mines in this county. ~1ining

activity for metals in San Bernardino County has been

very limited since 1960.

Some mining for metals is still being

done, but it is principally for gold, silver, and tungsten. Mining for other metals such as lead, copper, and zinc is minimal. Previous publications about mines in the county have generally made reference only to the production of ore minerals such as galena, pyrite, chalcopyrite, and barite.

There are, however, many

secondary minerals of little or no commercial value.

These

minerals not only produce beautiful specimens but are the core of the world-wide avocation of mineral collecting. The purpose of these reports is: (1)

to preserve as much data on the history of the mines as we can, before it is no longer available, and

(2)

to gather as much information as we can about the associated mineral species found at each mine.

Because of a lack of funding, extensive studies previously done by various State and Federal agencies have been brought to a virtual standstill.

Our volunteers hope that these reports will

partially fill the gap which has been created in the accumulation

-3

of information on our mineral resources. Mineral collectors sharing information they have or may acquire on mineral occurrences will help ensure the success of this program.

A simple note of mineral occurrences to the San

Bernardino County Museum, attention:

R. E. Reynolds, will be

appreciated. Reports for any mine will never be final as new minerals will continually be found.

Working cooperatively with the mineral

collecting community and mine owners, we hope to keep lists of species up to date.

Robert E. Reynolds Curator, Earth Sciences San Bernardino County Museum

-4

INTRODUCTION This report is directed toward the Blue Bell mine and adjacent prospects on the Blue Bell (Hard Luck) claims.

The

property has produced a large number of mineral species, some of which are rather rare on a world-wide scale. Many attractive hand specimens are covered with brightlycolored small to microscopic crystals which comprise the unusual mineral assemblage.

Magnification is necessary to fully appreciate

the crystal morphology and the sequence of crystallization of the species.

The Blue Bell claims, therefore, are a popular area for

those who specialize in the study of micromount mineral specimens. In 1977, t'lr. J. A. Crowley prepared an article on the minerals of the Blue Bell mine which was published in the Record

issue of November/December 1977.

Mineralogical

Thi s comprehensi ve arti cle

discussed those minerals which had been found at the Blue Bell mine up to that time. The article stimulated the interest of mineral collectors who have continued to find additional new minerals at the main mine workings.

Collectors expanded their investigations to additional

prospects located within the four Blue Bell claims.

Their findings

include more new minerals and different mineral assemblages. This report is an up-dating of

~iJr.

Crowley's report, and it

-5

is hoped that it will continue to encourage collectors to seek out other new minerals which probably occur at the Blue Bell mine and prospects. We wish to thank the following who have so graciously helped us in assembling the material contained in this report: Mr. Seldon C. Mahoney, owner of the mine, who has contributed most of the history of the mine, permits us to collect at the mine, and supplied supplemental ownership data; Mr. J. A. Crowley, who in addition to preparing the article in the Mineralogical Record, donated his Blue Bell study specimens to the San Bernardino County Museum; Dr. W. S. Wise, Department of Geological Sciences, University of California at Santa Barbara, and Dr. A. Kampf, Curator of Mineralogy, Los Angeles County Museum of Natural History, who confirmed the identification of minerals found at the mine by use of x-ray spectography and microprobe analysis; Jennifer Reynolds, who typed the final manuscript.

-6

LOCATION AND ACCESS The Blue Bell mine and its adjacent prospects are located in the Soda Mountains of San Bernardino County, California, about six miles north of Interstate Route 15 in the southeast quarter of Section 2, Township 13 North, Range 7 East, San Bernardino Base and

~~eri

di an.

Trona, California, U.S.G.S. Sheet, 1:250,000.

The mine ;s accessible to collectors in passenger vehicles with two-wheel drive, providing that caution is used during

-7

driving.

Interstate Highway 15 runs south of the mine.

The

Zzyzx Road offramp is located 56 miles northeast of Barstow, San Bernardino County, California, and 97 miles southwest of Las Vegas, Nevada.

The closest gasoline and supplies are located at Baker,

6.4 miles northeast of the Zzyzx offramp.

Gas can also be

obtained at Rasor Road, 6.1 miles southwest of the Zzyzx offramp. You will recognize the Zzyzx offramp as the only ramp whose name you can not pronounce.

Millard Maynard, the Cal Trans

engineer who developed the offramp, had to reorder the freeway sign several times before the spelling was correct.

At the offramp,

the collector goes north and then bears west following pavement. Before reaching a hill on the left (south), a dirt road leads northwest across a wash with palo verde trees.

This graded dirt

road heads west along the north side of the wash until it reaches a well-traveled track trending north, an obvious once-graded road which has survived many rainstorms.

Approximately 3.8 miles north

of the wash the Blue Bell mine prospects under claim are visible to the west.

A rough, gully-cut road runs westerly to the southern

Blue Bell workings.

Continuing north on the main road from the

Zzyzx offramp the traveler enters a narrow canyon, curving first west then south, where he arrives at the Blue Bell main workings, approximately 6.1 miles from the Zzyzx offramp.

A dozer road leads

31

7

18

IS

Baker and Soda Lake 15 minute topographi c maps, scale 1 :62 ,500.

1"

1 mile

--------

~--------------------------------------------------------------------------------------------"

-9

to the IIglory hole

ll

and adits where there is a remarkable view of

Soda Lake Valley and the road traveled to the mine.

-10

DESCRIPTION The Blue Bell claims are situated in the Mojave Desert. Vegetation is predominantly creosote scrub.

Temperatures range

well over 100 0 F. during summer months, and can dip below freezing during the winter.

It is frequently windy, a factor which

exacerbates the cold and provides no respite from the heat.

Auto-

mobile windshields and finishes can be pitted by blowing sand. The area receives little overall rainfall.

However, when rain

occurs, it is often torrential and accompanied by heavy thunderstorms.

These cloudbursts sometimes remove sections of paved and

unpaved roads.

The visitor should be aware of the dangers of

possible sheet flooding and flash flooding in canyons and washes. Mine tunnels on the Blue Bell claims can offer protection from heat, cold, wind, and rain.

The relative comfort of the

tunnels may also be sought by desert natives such as rattlesnakes. The Blue Bell area offers abundant space for dry camping. There are no lIimprovernents

ll

such as hook-ups or sanitary facilities.

Campers should bring their own firewood.

Both day trippers and

campers must be certain to carry adequate water supplies. Permission to collect on the Blue Bell claims should be gained from the owner, Seldon C. Mahoney.

Mr. Mahoney can be

contacted through R. E. Reynolds, Curator of Earth Sciences, San Bernardino County Museum.

-11 Mining was initially done at the Blue Bell mine (Claim No.1, Loc. 2A).

Later work on the adjacent claims resulted in five

prospects which were located in an area to the south of the mine. Under the cataloging system used by the San Bernardino County Museum, the Blue Bell mine is known as Location 1-71-2, where 1 71 2

= =

San Bernardino County Soda Mountains the numbered location of the Blue Bell mine.

Because of the number and variety of mineral species being found at each of the locations, they are cataloged as 1-71-2A, 1-7l-2B, etc. For this report, the locations will be referred to simply as Loc. 2A, Loc. 2B, and so on. The following sketches show the relationship of the Blue Bell mine within the claims, and claim and location markers .

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-13

The Blue Bell mine Loc. 2A consists of several short adits and small stopes.

The largest stope is approximately 22 feet

deep, 22 feet wide, and 13.5 feet high. a breccia cemented by mineralization.

The roof of the stope is A breccia is a mass of

broken rock, and the authors strongly caution collectors that work in this area can be hazardous. Loc. 2B is a horizontal adit located near the bottom of the hill.

This;s the tunnel developed by Mr. Atkinson which runs

several hundred feet into the hillside and includes drifts and stopes. Following the trail from Loc. 28 up the hill, one finds Loc. 2C.

This is also a horizontal adit, approximately 100 feet in

length, with a matrix of hard rock.

Several minerals have been

found at this location but it deserves more attention. Loc. 20 is located on the trail farther up the hill.

This

location is a twisting horizontal adit and vertical shafts.

The

matrix is a porous limonite alternating with metamorphic rock. Numerous minerals have been found at the site.

This is the

location erroneously called the Atkinson mine by previous collectors. Beautiful assemblages of various microminerals are still found at this location. Locs. 2E and 2F are short vertical shafts located to the

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north of the trail uphill from adit 2B.

These can be reached

by hiking south from the main Blue Bell workings (Loc. 2A). Leavi ng Locality 2D, they can be reached by hi ki ng uphi 11 over a large hypabyssal intrusion.

1.71.2A Blue Bell mine

main workings

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!l BLUE BELL PROSPECTS (not to scale)

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l-71-2C

The Blue Bell mine: view to the southeast toward the Zzyzx Road offramp on Interstate Highway 15. The access road to the Blue Bell glory hole (Loc. 2A) runs past the structures in the foreground. Oblique view, courtesy of Harris Aerial Photography, Yermo, California.

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Southerly view of road terminating at the Blue Bell mine main workings (2A). Courtesy Harris Aerial Photography, Yermo, California.

......

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Access road terminates at main Blue Bell workings (2A). Note foot trails that run easterly to adjacent prospects and lead to tunnel 2B. View south, courtesy of Harris Aerial Photography, Yermo, California.

......,

View west across Blue Bell claims. Access road to main workings (2A) is in distance. Access road to tunnel (2B) is in foreground. Prospects 2E and 2F appear directly above tunnel 2B. Prospects and tunnels 2C and 2D are uphill and southerly (left) of tunnel 2B. Courtesy Harris Aerial Photography, Yermo, California.

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HISTORY Originally known as the Hard Luck claims 1, 2, 3, and 4, this area was opened prior to 1920.

From at least 1920 the claims

were owned by Mr. Charles Reat until his death in 1952. There is no record of production at the claims until 1949 when according to L. A. Wright, et al. (1953, p 101) about 80 tons of lead-silver-copper ore were shipped from the Blue Bell (Hard Luck) mine to Selby, California.

The ore was composed principally

of chrysocolla, malachite, cerussite, galena, and chalcopyrite in a carbonate gangue and had a smelter recovery of 11% lead, 4.5% copper, and 4 ounces of silver per ton of are.

Wright reported

that the known minable ore bodies were removed. He further reported that the mine was owned by Mr. Frank Baker of Barstow, California and leased to Mr. R. V. Waughtel of Manix, Ca 1i forn i a. J. G. Goodwin in his report on lead and zinc in California

(1957) reported separately on the Blue Bell mine and on the Hard Luck group.

He reported (page 616) that the mine was worked

again in 1951 with the ore being shipped to Selby, California. The average of the 1949 and 1951 productions showed an average smelter recovery of 7.5% lead, 0.95% copper, 5.31 ounces of silver per ton of ore, and some gold.

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The above averages support Wright's statement that minable ore bodies were removed by 1949 since the ore mined in 1951 would have to have been of a poor quality to bring the amounts of lead down from 11% to 7.5% and copper down from 4.5% to 0.95%. The above reports by Wright and Goodwin are apparently in error since the mine was owned by Mr. C. Reat.

It is probable

that Mr. Baker was only operating the mine for Mr. Reat as he was known to be doing during the period 1952-1955. Goodwin in the same report (page 639) discusses the Hard Luck group as an apparently different location than the Blue Bell mine. He reports that complex ore from this location was shipped to Midvale and Tooele, Utah, in 1951 and 1952.

The average smelter

recovery for these two years was 8.2% lead, 0.854% copper, 2.75% zinc, 6.45 ounces of silver per ton of ore, and some gold. According to Goodwin, the owner was Mr. C. Reat of Inglewood, California, with Mr. Frank Baker as the operator. In analysing the smelter recovery reports, it is interesting to note that the recovery from the Hard Luck group showed 2.75% zinc but that no zinc was reported in recoveries from the Blue Bell mine.

It is theorized, therefore, that ore taken from the so-

ca~led

Hard Luck group was actually taken from Loc. 20 in the

prospects south of the Blue Bell mine.

This possibility is

further strengthened by the following comparison of the minerals

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which have been found at the two locations: (1)

there has been no evidence of sphalerite being found at the Blue Bell mine; however, casts of sphalerite have been found at Lac. 2D;

(2)

secondary zinc minerals (hemimorphite, willemite, etc.) have been very sparse at the Blue Bell mine but they are very abundant, particularly hemimorphite, at Loc. 20 in the prospects south of the mine.

Following the death of Mr. C. Reat in 1952, ownership of the property was taken over by Mrs. Maude L. Reat and her son-in-law and daughter, Seldon C. and Ardith B. Mahoney. Their records show that Mr. Frank Baker operated the claims during the years 1952 through 1955, apparently under a prior verbal arrangement with Mr. C. Reat.

He was probably doing the

same in 1949-1951 as stated above. These records include one processing report from Midvale, Utah, which shows that on March 5, 1952 a shipment of 28.06 tons of ore from the claims was processed. The smelter recovery from this shipment was reported as 6.7% lead, 0.76% copper, 8.4% iron, 3.10% zinc, 9.30% lime, 0.80% sulfur, 5.20 ounces of silver per ton of are, and 0.01 ounces of gold per ton of ore.

Zinc is again reported and, also, a

relatively high percentage of iron.

There was very little in the

form of iron matrix or minerals found at the Blue Bell mine. matrix of minerals found at Loc. 20 is very rich in iron.

The

This

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supports the theory that Goodwin's "Hard Luck group" was probably Loc. 2D. The owners suspect that other shipments were made during this period but have no records to verify this. On January 15, 1957, the Hard Luck claims were leased to Mr. W. A. Park of Lynwood, California with the stipulation that he perform annual labor necessary to constitute assessment work each year the lease was in effect and to have it properly recorded in the owners name.

He neglected to do so and the lease was

nullified for non-performance in January 1958. In order to protect their interests, Seldon C. and Ardith B. Mahoney, who were now owners of the property, had a notice of location recorded on January 28, 1958, for each claim wherein the name of the claims was changed from Hard Luck Nos. 1,2,3, and 4 to Blue Bell Nos. 1, 2, 3, and 4. On February 14, 1958, the claims were leased to Mr. W. B. Long of Los Angeles, California.

The lease was subsequently

nullified for non-performance and it is not known whether or not he shipped any ore. During recent years the only work at the claims has been done by mineral collectors for the assemblage of microminerals.

At

first this collecting was limited to Loc. 2A (the Blue Bell mine), but the search soon led to exploration of the prospects to the

-23

south of the mine. Many new mineral species and assemblages have been found at these prospects, principally at Loc. 20. It is interesting to note that this location was once misnomered the "Atkinson mine" by collectors, and is listed as such on the Trona sheet of the California Division of Mines (Jennings et al. 1962). The present owners advise that Mr. Atkinson worked one of the prospects (Loc. 2B) starting in 1955 or 1956 without permission of the owners.

His contention that he was working on an area

adjacent to the Blue Bell claims was incorrect and he was forced to discontinue his work. Any mineral specimens which have been labeled as being from the Atkinson mine should be changed to the Blue Bell claims. The claims are still known as the Blue Bell Nos. 1, 2, 3, and 4, and are still owned by Seldon C. and Ardith B. Mahoney.

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GEOLOGY Geologic mapping of the Soda Mountains was initially done by Grose (1959); his work is summarized by Jennings, et al. (1962). The northern Soda Mountains are generally considered as that portion north and west of Interstate Highway 15. The oldest rocks exposed in the northern Soda Mountains are marine carbonate sediments deposited during the late Paleozoic and early Mesozoic eras.

Fossils suggest that the age of the

depositional sequence was through the Carboniferous, Permian, and Triassic epochs.

Doug Walker (in Marzolf and Dunne, 1983) from

the Massachusetts Institute of Technology is currently mapping a detailed stratigraphic section in the northern Soda Mountains. In a paleogeographic reconstruction of the Soda Mountains, Marzolf (1982) describes the original marine carbonate sequence that was subsequently intruded and covered by Triassic volcanic rocks.

In early Jurassic times these rocks were covered by

extensive dune sands. During the late Mesozoic, the area was intruded by granitic rocks and subsequently by extensive hypabyssal dikes.

Such intru-

sions altered the carbonate sediments, the volcanics, and the clastic dune sands to marble and chert interfingered with calcsilicate skarn as well as metavolcanic rocks, quartzites, and

-25

banded hornfels.

These rocks are brittle, sometimes porous, a

combination that made them an excellent host for later mineralization. During the Cenozoic era, possibly in Miocene times, the northern Soda Mountains received deposits of andesite (Jennings, et al. 1962) and volcanic ash (Henderson, 1980).

The volcanic

ash, perhaps deposited in a lake, can be seen at the Pink Lady bentonite mine directly north of the Zzyzx offramp. Faults plotted by Grose (1959) may have been active in late Tertiary and early Quaternary times after mid-Tertiary deposition of volcanic ash. None of the work by the above authors specifically addressed the timing of emplacement of the sulfide ore body at the Blue Bell mine.

Crowley (1977) suggests correctly that mineralization was

contemporaneous with or later than granitic rocks.

~lteration

of the Mesozoic

However, additional detailed field investigation

and mapping will be necessary to adequately attribute ore mineralization to any specific Tertiary event.

-26

MINERALOGY Forty-five minerals and potential for four unknown minerals have been found at the different Blue Bell prospects. The original sulfide ore body and associated gangue minerals were emplaced by hydrothermal solutions against traps and in reservoirs in the cold host rock.

Later, the ore body was

gradually exposed and oxidized by ground water percolating through the brecciated rock. Crowley (1977) suggests that the original constituents of the ore body were galena, sphalerite, chalcopyrite, hematite, and quartz.

Galena, hematite, and quartz are the only hypogene minerals

that remain.

Galena is probably the source of the fifteen oxide

minerals that contain lead, and may also be the source of the silver minerals.

Sphalerite is absent but the presence of aurichal-

cite, rosasite, smithsonite, willemite, and especially the abundant hemimorphite suggest that a zinc sulfide was present.

Chalco-

pyrite is reported as part of the ore processed from the "glory hole" (Loc. 2A) but has not been collected recently.

There are

twelve secondary minerals found at the mine that contain copper. Crowley (1977) suggests that the absence of pyrite from the hypogene ore body at the main Blue Bell workings is probably a significant factor in the supergene mineral assemblage that remains.

-27

This may be a valid postulate that links the supergene deposition of the main ore body at the "gl ory hole" (Loc. 2A) with the tunnel developed by Mr. Atkinson (Loc. 2B). In contrast, Locs. 2C through 2F, particularly Loc. 20, consist of abundant goethite and limonite boxwork suggesting the presence of pyrite in the hypogene assemblage.

Goethite pseudomorphs

found at Loc. 20 appear to be of two types.

Those approximating

cubic habits may have originally been galena or pyrite.

Those

with orthorhombic habits may have replaced anglesite or barite.

-28

LIST OF MINERALS Angl esi te

PbS0 4

Apatite

Ca5(P04)3F

Aurichalcite

(Zn,Cu)5(C0 3)2(OH)6

Brochanti te

CU4(S04)(OH)6

Ca 1cite

CaC0 3

Caledonite

Pb 5Cu 2(C0 3) (S04)3(OH)6

Cerussite

PbC0 3

Chalcanthite

CuS04· 5H 20

Chalcopyrite

CuFeS2

Ch 1orargyrite

AgCl

Chrysocolla

(Cu,Al)2H2Si205(OH)4'nH20

pseudo aft. aurichalcite pseudo aft. caledonite pseudo aft. hemimorphite pseudo aft. kaolinite pseudo aft. malachite Dioptase

CUSi0 2 (OH)2

Embol i te

Ag(Cl,Br)

Epi dote

Ca2(Al,Fe+3)3(Si04)3(OH)

Fl uor; te

CaF 2

Fornaci te

(Pb,Cu)3[(Cr,As)4 J2(OH)

Ga lena

PbS

-29

Goethite

alpha-Fe+ 30(OH)

Gold

Au

Grossular garnet

Ca 3A1 2(Si0 4)3

Gypsum

CaS04' 2H 20

var, satin spar Hematite

alpha-Fe 203

Hemimorphi te

Zn4Si207(OH)2'H20

Jarosite

KFe3(S04)2(OH)6

Kaolinite Kettnerite

A1 2Si 205 (OH)4 CaBi(C0 3)OF

Leadhi 11 ite

Pb 4(S04)( C03)2(OH)2

Linarite

PbCu(S04) (OH)2

Magneti te

Fe+2Fe2+304

Malachite Minium

CU2(C03)(OH)2 Pb-+ 2Pb+ 404

Murdochite

PbCu 6(O,Cl,Br)8

Peri te

PbBi 02Cl

Pl attnerite

Pb0 2

Plumbogummite (?)

PbA1 3(P0 4 )2(OH)5'H 20

Pyrite (?)

FeS2

Pyrol usite

Mn02

Pyromorphite

Pb 5(P0 4)3Cl

-30

Quartz

Si0

Rosasite

(Cu,Zn)2(C0 )(OH)2 3

Smithsonite ( ?)

ZnC0 3

Sphalerite (?)

(Zn,Fe)S

Tsumebite

Pb 2Cu(P0 4 )(S04)(OH)

Wulfeni te

PbMo0 4

Willemi te

ZnSi0 4

Unknown Mi nera 1 A Unknown Mi nera 1 B Unknown Mineral C Unknown Mi nera 1 0

2

-31

DESCRIPTION OF MINERALS NATI VE ELEt1ENTS

Gold

Au

There are no known specimens of gold from these locations, although smelter recovery records indicate that gold was present (Goodwin 1957, S.C. Mahoney, p.c. 1983).

SULFIDES Chalcopyrite No specimens of chalcopyrite are known.

However, the mineral

was reported by Wright, et al. (1953) to have been one of the components of the ore taken from Loc. 2A in 1949-1950. Galena

PbS

Specimens of galena have been found at Loc. 2A.

It occurs

as bright cleavages in thin seams coated with gray and brown oxide minerals.

It was reported in Wright, et al. (1953) as one

of the components of the ore mined at Loc. 2A in 1949-1950. Goethite pseudomorphs from Loc. 20 that have a cubic habit may be after galena or, possibly, pyrite. Pyrite (?) Goethite boxwork is abundant at Loc. 20 in contrast to other

-32

areas.

Cubic goethite pseudomorphs at this locality may be

after pyrite or galena. Sphalerite (?)

(Zn,Fe)S

Sphalerite has not been found at any of the locations.

It

is considered, however, to have been one of the hypogene minerals because of the abundant secondary zinc minerals present at the mine (Crowley 1977).

OXIDES

Goethite

alpha-Fe+ 30(OH)

Goethite has been reported from Loc. 20.

It occurs as small

honey-colored balls with a radiating crystal structure.

Goethite

boxwork and goethite pseudomorphs also occur at Loc. 20. Hematite The specular variety of hematite is reported from Loc. 2A by Crowley (1977) and flat blades of hematite have been reported from cavities in the garnet-rich host rock. At Loc. 20 hematite occurs as irregular single and multiple crystals in a granular auartz matrix filling rectangular cavities apparently left by sulfide minerals.

When broken, the color

transmitted from the partings is a deep ruby-red.

The streak is

-33

reddish-brown.

Fragments are not magnetic but are sometimes

intergrown with magnetite. Magnetite Magnetite has been found at Loc. 20 as black octahedral and dodecahedral crystals.

These occur with granular quartz and

irregular hematite crystals within rectangular cavities apparently left after sulfide minerals were oxidized.

The crystals are black

on broken surfaces and have a black streak.

They are easily

attracted to a magnet or magnetized needle.

On one specimen the

dodecahedrons are coated with clear quartz and also covered with a thin layer of chalcedony. Minium Minium has been found at Loc. 20 as red secondary coatings around vugs possibly left by galena. Murdochite r1urdochite occurs as black, cubic crystals at Lac. 2A where it is associated with chrysocolla pseudomorphs.

It is

also found at Loc. 20 as black cubic crystals and masses on wulfenite and on blades of chrysocolla pseudomorphs.

The

murdochite sometimes completely replaces the wulfenite. Murdochite octohedrons (W.S. Wise) occur on hemimorphite at Lac. 20.

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Black cubes of murdochi te (0.05 mm) on 1.7 mm spray of blue auri chalci te. Sugar Whi te specimen and photograph.

Pl attneri te Plattnerite has been found as black acicular crystals and masses on calcite rhombs at Loc. 2A and at Loc. 2D.

At Loc. 2B

brilliant black, short, equidimensional crystals of plattnerite have been found in stopes along the adit. Pyrol usite Dendrites in fractures and black earthy masses found at Locs. 2A and 20 appear to be pyrolusite.

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HALIDES

Ch 1orargyri te

AgCl

Chlorargyrite was reported to have been found at Loc. 2A by Croy/ley (1977).

He reports that it is inconspicuous but

relatively common when looked for.

It is associated with

chrysocolla, quartz, and dioptase in black to brown siliceous ore.

The chlorargyrite occurs as brown to purplish-brown cubes

and cubo-octahedrons.

The crystals are seldom over a few mm in

size. Some have expressed concern that this occurrence may have been embolite, which has since been found at this location and which has been verified by microprobe by Dr. W. S. Wise, University of California, Santa Barbara (UCSB).

See description of embolite,

foll owi ng. Embolite

Ag (Cl ,Br)

Embolite occurs as yellowish and olive-green crystals and waxy masses at both Loc. 2A and Lac. 20. confinned by microprobe analysis by Dr.

Its identity has been ~J.

S. Wise, UCSB.

Dr.

Wise uses the name "embolite" for the silver mineral which has approximately equal proportions of bromine and chlorine.

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Greenish-yellow embolite crystal. specimen and photograph.

John Jenkins

At Loc. 2A embolite is generally associated with chrysocolla. At Loc. 20 it is more widespread and is found individually and in association with hemimorphite, quartz, calcite, fluorite, and perite.

Occasionally all are found on the same specimen.

Several specimens show olive-green embolite crystals in parallel growth over brownish to black crystals which are also apparently embolite.

The color of embolite with a higher bromine

content is said to be less stable than that with a high chlorine content.

The color change noted above may suggest a decrease

in bromine with continued deposition of embolite.

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Fl uori te

Clear colorless fluorite. John Jenkins specimen and photograph.

Clear colorless fluorite cube (2.7 rrun) with fan ofhemimorphite. Sugar Whi te specimen and photograph.

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Colorless, transparent cubes and octahedrons of fluorite occur at Loc. 2A; the cubic form is most common.

Fluorite

crystallized late and Crowley (1977) reports that it has been found on all of the minerals except brochantite. At Loc. 2D fluorite is found with hemimorphite, quartz, embolite, wulfenite, murdochite, calcite, kettnerite, and perite. It occurs as clusters of intergrown crystals which are occasionally tinged lavender or purplish at the edges or zoned purple in th~

center. Opaque purple octohedrons also occur. Clear, colorless crystals of fluorite with inclusions of

chrysocolla pseudomorphs make very attractive specimens.

CARBONATES

Aurichalcite Crystals of aurichalcite have been identified by x-ray analysis by Dr. A. Kampf, Los Angeles County Museum of Natural History (LACM).

The crystals were found at Loc. 2C associated

with hemimorphite.

The crystals are clear, aquamarine in color,

and are flat with a blunt termination. Aurichalcite occurs sparingly at Loc. 20 as spherules of sky-blue radiating crystals.

Pseudomorphs of chrysocol1a

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presumably after aurichalcite are found at Loc. 2D. Calcite Calcite was one of the last minerals to crystallize at the Blue Bell.

At Loc. 2A it occurs as clear, colorless rhombo-

hedrons usually associated with dioptase and as crystals (Crowley 1977).

It

c~rved,

bladed

has also been found at this location

as groups of six-sided, clear colorless crystals. At Loc. 20 calcite has been found as multi-faced crystals associated with hemimorphite, quartz, fluorite, and embolite. It also occurs as clear bladed crystals on quartz and associated with fluorite.

Calcite was recently found at Loc. 20 as white,

curved, flat crystals resembling wood shavings.

At Loc. 2B matrix

is covered with scalenohedral calcite crystals. Cerussite Cerussite occurs at Loc. 2A as clear coatings showing crystal faces and striations on matrix with tsumebite and kaolinite, sometimes enclosing both.

In the same area, it is

found with and coating chrysocolla pseudomorphs. Crowley (1977) records bladed cerussite crystals, usually stained red-brown, which predate the sulfate minerals and have linarite, caledonite, and leadhillite formed on them, and as

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milky white subhecral crystals which formed late in the sequence at Loc. 2A. Kettneri te Kettnerite has been identified by x-ray diffraction and microprobe methods by Dr. s~uare

~.

S. Wise, UCSB.

It occurs as white

plates having a pearly micaceous luster.

These are grouped

in irregula.r masses and balls associated with perite, hemimorphite, embolite, fluorite, and chrysocolla pseudomorphs at Loc. 2D. Leadhi 11 ite Colorless to pale ice-blue milky coatings of leadhillite have been found at Loc. 2A, often associated with caledonite, sometimes with linarite, and rarely with dioptase or cerussite. Individual crystals a few mm in size form aggregates of up to several square cm.

The pseudohexagonal crystals have the c-axis

approximately normal to, parallel to, or slightly inclined to the matrix (Crowley 1977). Malachite Malachite has been found at Loc. 2D with hemimorphite and aurichalcite, and altering to chrysocolla.

Malachite occurs as

flat fronds of green crystals in loose bundles, sometimes

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isolated but commonly in mounds radiating from a central source. Rosasite Light green, fuzzy, powdery coatings of rosasite are found on some of the minerals at Loc. 2A (Crowley 1977). Smithsonite (?) Black oxides form casts over scalenohedral crystals which may have been smithsonite at Loc. 2D.

SULFATES Anglesite Coatings of milky white subhedral anglesite crystals with a greasy luster occur at Loc. 2A, often coated with linarite and sometimes with caledonite or brochantite.

Brilliant colorless

druses of angelsite crystals also occur covered with linarite and caledonite (Crowley 1977). Goethite pseudomorphs with an orthorhombic habit from Loc. 2D may be after ang1esite. Brochantite Brochantite has been found at both Locs. 2A and 2B.

At Loc.

2A it occurs as deep green crystals of acicular to stubby prismatic

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habit.

It usually occurs with linarite and also has been found

associated with anglesite, hemimorphite, and caledonite (Crowley 1977).

Brilliant green brochantite crystals on and being

replaced by chrysocolla are found at Loc. 2B associated with 1inari te. Caledonite At Loc. 2A caledonite occurs as fine, flat-lying bright turquoise-blue crystals up to 2 cm in length, and growing from sides of fissures as stubby prismatic crystals up to several mm long with roundish and poorly-developed terminations.

It occurs

with 1inarite, leadhi 11 ite, anglesite, and sometimes '.'/ith cerussite and dioptase.

Fine druses of caledonite with linarite and/or

leadhi11ite reach 10 x 15 cm.

Caledonite and linarite commonly

grade into each other in the same crystal; both were among the earliest minerals to crystallize (Crowley 1977).

Caledonite

replaced by chrysocolla and associated with fornacite has also been found at Loc. 2A. Cha 1canthite Chalcanthite has been found at the Atkinson tunnel, Loc. 2B. It occurs as bright blue fibrous crystals and occasional "rams horns" lining seams.

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Gypsum The satin spar variety of gypsum has been found at Loc. 2A. At Loc. 20 gypsum variety satin spar is found as loose "rams horns " associated with fluorite and dioptase. Jarosite Jarosite has been found at Locs. 2A and 20 as brownish resincolored pseudo-cubic crystals and as flat crystals with large c-faces. Linarite Brilliant royal blue bladed crystals of linarite up to three cm long are relatively common at Loc. 2A.

The longer crystals

usually lack good terminations in contrast to smaller transparent crystals because of contact with matrix or other minerals. crystals are striated parallel to the long axis.

The

Since linarite

crystals have been reported with cerussite cores, it may replace cerussite.

Linarite also replaces or is replaced by caledonite

and brochanthite (Crowley 1977). Linarite has also been found at Loc. 2B with, on, and altering to chrysocolla and in association with brochantite.

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CHROMATES

Fornacite Fornacite was found at Loc. 2A in 1983.

It occurs as small,

dark olive-green, bladed crystals associated with fluorite, dioptase, wulfenite, and cerussite.

A granular yellow-green

mineral often found associated with fornacite has the same streak and may also be fornacite.

Dark olive-green fornacite crystal (0.8 mm). Sugar White specimen and photograph.

PHOSPHATES Apatite Apatite crystals occur at Loc. 20 as squat barrels on jarosite and as spheres, hemispheres. and rarely as fans

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of loosely knit, equal length crystals radiating from a common center.

Individual crystals appear hexagonal with a pinacoid

termination and are clear to white. Plumbogummite (?) A mineral of similar composition to that of plumbogummite occurs as yellow-green halos and crusts in association with tsumebite at Loc. 2A.

This identification is only tentative

because there is insufficient material for an x-ray diffraction photograph.

The microprobe (Wise, UCSB) detected major amounts

of Pb, Al, and P. Pyromorphite Pyromorphite has been found as white to yellow prismatic crystals associated with tsumebite and kaolinite at Loc. 2A. In tunnel 2C it occurs as green hexagonal crystals with pinacoidal terminations.

It is found at Loc. 2E as very minute yellow

hexagonal crystals.

These pyromorphite specimens were analysed

with microprobe by Dr. W. S. Wise (UCSB). Tsumebite Tsumebite has been found at Loc. 2A where it occurs as complex, emerald-green crystals associated with cerussite, pyromorphite, plumbogummite (?), and kaolinite.

It was identified

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by x-ray methods (A. Kampf, LACM).

ANTI MONATES

Peri te Perite has been identified by x-ray analysis' by Dr. A. Kampf (LACM) as occuring at Loc. 20.

It is found as yellow mica-

ceous masses associated with kettnerite, hemimorphite, embolite, fluorite, quartz, and chrysocolla pseudomorphs. Perite was apparently one of the earlier minerals formed at this location as it is found embedded in the limonitic matrix and coated with quartz druses which sometimes line the vugs in the matrix.

MOLYBDATES Hulfenite At. Loc. 2A wulfenite occurs as yellow tabular crystals of varying forms about 1 mm in size.

Wulfenite crystallized

late in the sequence and usually occurs by itself or on dioptase. (Crowl ey 1977). It is also found at Loc. 2A as small, bright-yellow to orange-yellow amoeba-like blebs lying flat on the matrix.

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Clear yello.v wulfeni te crystal wi th fans of hemimorphi te. John Jenkins specimen and photograph.

Clear yellow wulfenite of fluori te (largest.6

(largest 2.5 rom) and clear colorless cubes Sugar Whi te specimen and photograph.

11l1W.

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Wulfenite occurs at

Lo~.

20 as clear to cloudy yellow tabular

crystals with variable pyramid faces.

It is with or covered by

fluorite, dioptase, hemimorphite, and murdochite.

Murdochite

in some instances completely replaces the wulfenite.

SILICATES Chrysocolla Chrysocolla occurs at both Locs. 2A and 20 as beautiful sky-blue pseudomorphs after aurichalcite, hemimorphite, malachite, and occasionally caledonite and kaolinite. At Loc. 2A chrysocolla is found associated with embolite, dioptase, quartz, and chlorargyrite.

It can occur pseudo-

morphic after caledonite in sharp crystals.

It also replaces

kaolinite and is covered with orange or pale yellow pyromorphite crystals. At Loc. 20 is is found intergrowing with clear colorless cubes of fluorite and emerald-green dioptase crystals.

All of

these are sometimes found on the same specimen. It is also found as inclusions in clear, colorless cubes of fluorite.

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Spray of sky-blue chrysocolla after ma.i achi te (1.4 mm). Sugar White specimen and photograph.

Chrysocolla pseudomorphs, possibly after malachite, with clear colorless fluori te cubes. John Jenkins specimen and photograph.

L -_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _._ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

~

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Dioptase Brilliant light emerald-green druses of acicular to rod-shaped microscopic dioptase crystals with flat and pyramidal terminations occur at Loc. 2A.

Found in the periphery of the

ore body, it formed on most of the minerals present, and is commonly associated with chrysocolla.

Although dl0ptase formed

late in the crystal sequence, it is often coated with chlorargyrite (Crowley 1977). At Loc. 2D dioptase if found with chrysocolla pseudomorphs, fan-shaped aggregates of hemimorphite crystals, clear colorless fluorite, quartz, and gypsum.

It occurs as individual crystals

and groups of crystals. Epidote Bright, transparent, olive- to pistachio-green crystals of epidote are found in flat-lying groups filling and coating fractures in the host rock at Loc. 2E. Grossular Garnet Yellow crystals and masses of grossular garnet have been found at Locs. 2B and 2D restricted to calcite-filled vugs in the host rock.

These vugs have occasionally been emptied of

calcite and now contain secondary minerals deposited upon the garnet.

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Hemimorphite Small transparent blades of hemimorphite are common in the peripheral areas of Loc. 2A, generally in the same areas as dioptase and other silicates (Crowley 1977). At Loc. 20 it is even more common.

It occurs as sprays of

crystals sometimes sprinkled with microscopic clear colorless singly and doubly terminated quartz crystals, clear colorless cubes of fluorite, and multi-faced calcite crystals.

It can be

associated with perite, kettnerite, and olive-green crystals and masses of waxy embolite on a limonite matrix.

Clear colorless hemimorphite crystals form rosette. John Jenkins specimen and photograph.

It also occurs as fan-shaped aggregates of clear crystals

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associated with dioptase, fluorite, and sky-blue chrysocolla pseudomorphs of various minerals. Some specimens have tightly grouped flat-lying crystals of hemimorphite which resemble buttons and are blackish in color. These are usually associated with quartz.

Other specimens show

hemimorphite as branching groups of clear, striated crystals in nearly parallel position tapering down to a point.

These are

associated with quartz which lines the vugs in the limonite matrix. Hemimorphite also occurs as short blocky prismatic crystals both singly and doubly terminated and associated with clear to cloudy singly and doubly terminated quartz crystals, emeraldgreen dioptase, and sky-blue chrysocolla pseudomorphs. Kaolinite Kaolinite occurs at Loc. 2A as white spherules which are associated with pyromorphite, tsumebite. and chrysocolla pseudomorphs.

It has been identified by x-ray diffraction by

Dr. W. S. Wise (UCSB).

At this locality. the chrysocolla may

have replaced kaolinite. Quartz Tiny transparent, sparkly crystals of quartz are associated

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with other silicate minerals at Loc. 2A.

It appears to have

crystallized late in the sequence (Crowley 1977). At Loc. 20 quartz appears to have crystallized in two stages.

It is found as masses and crystals as part of the

limonitic matrix.

It is also found as clear to milky-white singly

and doubly terminated minute crystals growing on nemimorphite and on blades of chrysoco1la pseudomorphs.

It can be associated

with perite, fluorite, embolite, and calcite. Wi llemi te Willemite has been found at Loc. 20 where it occurs as short, hexagonal, colorless crystals forming radiating sprays in association with hemimorphite.

It has been identified by Dr. A.

Kampf (LACM) by x-ray analysis.

UNKNOWN MINERALS

Unknown Mineral A is found at Lac. 20 forming white casts after hemimorphite, sometimes with clear fluorite cubes on the casts. Unknown Mineral B occurs at Lac. 20 as black granular coatings on grossu1ar garnet crystals and masses.

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Unknown Mineral C is found at Loc. 20 as a black mineral either coating or replacing hemimorphite. Unknown Mineral D occurs at Loc. 2D as a black mineral layered between perite and quartz in vugs in the limonitic matrix.

Unknown mineral A, white casts after hemimorphite. Sugar White specimen and photograph.

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PARAGENESIS The hypothetical suite of hypogene minerals deposited in the vicinity of workings Loc. 2C and 20 may have been somewhat different than those that Crowley (1977) suggests were deposited at the main Blue Bell workings.

Geographically, the latter would

appear to include Localities 2A and 2B described herein.

Because

of apparent differences, we have included Crowley's paragenesis which is followed by a discussion of minerals from Locs. 2C/20. The great variety ·of minerals, reversals in crystallization sequence, and rapid changes in mineral assemblages in the same fissure both vertically and laterally over the space of a few cm or less make the application of Eh-pH diagrams difficult. The Eh-pH conditions in the solutions apparently changed considerably during secondary mineral formation. Some general observations can be made about the assemblages however. Conditions were initially near neutral, which allowed the cerussite to form. With time, the solutions became progressively more acidic and finally a reversal toward higher pH and eventually mildly alkaline conditions occurred. The acidic conditions through most of the time of secondary mineral formation would account for the general lack of limonitic minerals in the Blue Bell mine [Loc. 2A], the iron having been carried away by the acid solutions. In addition, a pyrite-deficient hypogene assemblage would also help to explain the lack of limonitic material. According to Jarrell (1944) brochantite forms from mildly acid, dilute sulfate solutions. The transition from neutral to acidic conditions probably coincided with the formation of brochantite. Then the transition from acidic to alkaline conditions occurred after the formation of the second stage brochantite. The formation of the hemimorphite-dioptasewulfenite mineral assemblage then occurred under neutral to alkaline conditions, after the cessation of the crystalli-

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zation of brochantite. The solutions in the ore body were initially copper bearing, and became progressively enriched in lead and other ions as oxidation progressed and pH dropped. These types of conditions would explain the assemblage in order of crystallization of brochantite --~ linarite --~ caledonite + anglesite. When conditions began to change towards higher pH, these minerals again came into their stability field and crystallized in the reverse sequence; caledonite --~ 1inarite --~ brochantite with excess lead forming anglesite or combining with carbonate to form cerussite. As stated by Takahashi (1960), anglesite and cerussite are metastable under neutral conditions. (Crowley 1977)

At Locations 2Cj2D the presence of pyrite in the original sulfide pod is suspected because of the abundance of goethite and other iron oxides and sulfates, as well as the presence of cubic pseudomorphs.

The presence of galena (argentiferous?), sphalerite,

and chalcopyrite is suggested by the relatively abundant zinc, copper, silver, and lead minerals.

Two secondary minerals suggest

that bismuth may have been present as bismuthinite or within another sulfide (galena?).

Orthorhombic pseudomorphs suggest the

presence of anglesite, or possibly barite, as a gangue mineral. The primary sulfide ore body may have included metals such as iron,

zinc~

copper, lead, silver, and bismuth (?).

After

emplacement, it may have been oxidized, as Crowley suggests, by near-neutral solutions.

The copper and lead groups dispersed

while the iron group remained.

The minerals used by Crowley as

indicators of high acid conditions are not present at Locs. 2Cj2D.

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Alkaline conditions may have caused crystallization of magnetite and hematite locally within goethite pseudomorphs.

Perite

crystallized soon after, and is the earliest identified bismuth mineral in the 2C/20 suite.

The iron oxides and perite were

then coated with a first generation of quartz. The carbonate minerals malachite, aurichalcite, and smithsonite (?) appear to be the earliest secondary copper and zinc minerals to crystallize at prospects 2Cj2D.

Silicate-rich solutions

then monopolize the zinc and copper, forming hemimorphite and chrysocolla.

The latter often replaces the former, as well as

the carbonate minerals.

Fluorite, rare in oxidized zones (Palache

et al. 1944), crystallized from this point on, until late in the sequence. A change in supergene deposition is implied when the deposi-tion of chrysocolla and hemimorphite gave way to the deposition of willemite and then a second generation of quartz.

Around this

time, the crystallization of jarosite was followed by apatite, the earliest phosphate, and kettnerite, the latest bismuth mineral.

Subsequently, pyromorphite and wulfenite crystals preci-

pitated.

The latest lead minerals to occur were plattnerite

and murdochite, the latter sometimes entirely replacing wulfenite. Subsequently, fluorite and dioptase crystals proliferate and

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are intermixed with embolite.

The only minerals to crystallize

1ater at Locs. 2C/2D are calcite, auri cha 1cite, and gypsum. The paragenetic sequence at Locs. 2C/2D suggests that oxidation of the original sulfide body produced oxides of iron and lead/bismuth, followed by copper carbonates. Successive deposition was influenced by silica-rich fluids. Seven mineral species contain bromine, chlorine, and fluorine. There is a possibility that these halogens and phosphorus were introduced with the siliceous fluids.

Their abundance raises the

question of whether the silica-rich solutions coincided with or followed local mid-Tertiary siliceous eruptions in the Mojave Desert. \~ulfenite

was formed by reacti on of lead in the deposit with

molybdate radicals transported from relatively distant porphyrys. Phosphates such as pyromorphite are rare in the southwestern United States.

The lack of arsenate minerals at the mine may

reflect an absence of arsenic in the sulfide ore body. The source of the elements of the latest minerals to crystallize, carbonates and sulfates of calcium and zinc, are available locally. They were deposited by percolating ground water. There are apparent variations in mineral species and sequence of deposition between the main workings (Locs. 2A/2B) and those prospects to the south (Locs. 2C/2D).

The lack of similarity may

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partially be due to compositional differences in the original sulfide bodies.

The alteration of these sulfide bodies may

have been by fluids of differing degrees of acidity. Altogether, the suite of minerals from the Blue Bell claims is rare, colorful, and offers further opportunity for detailed study as well as enrichment of species, locality: and micromount mineral collections.

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REFERENCES Crowley, J.A., 1977. r1inerals of the Blue Bell mine, San Bernardino County, California. The Mineralogical Record, Vol. 8, No.6, pp 494-496, 518. Goodwin, J.G., 1957. Lead and zinc in California. California Journal of Mines and Geology, Vol. 53, pp 353-724. Grose, L. T., 1959. Structure and petrology of the northeast part of the Soda r~ountains, San Bernardino County, Cali forni a. Geological Society of America Bulletin 70, pp 1509-1548. Henderson, G. V., 1980. Geology of the Pink Lady bentonite mine, Zzyzx, California, in Geology and mineral wealth of the California desert,IFife and Brown, eds. South Coast Geological Society, p. 278. Jarrell, 0. W., 1944. Oxidation at Chuquicamata, Chile. Geology, 39, pp 251-286.

Economic

Jennings, C.W., J.L. Burnett and B.W. Troxel, 1962. Geologic map of California, Trona sheet, 1 :250,000. California Division of Mines and Geology. Marzolf, John C., 1982. Paleogeographic implications of the early Jurassic (?) Navajo and Aztec sandstones. Geological Society of America Abstracts of Programs. Palache, Charles, H. Berman, and C. Fronde1, 1944. The system of mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Seventh Edition, Vo1s I, II. John Wiley and Sons, New York. Takahashi, T., 1960. Supergene alteration of zinc and lead deposits in limestone. Economic Geology, 55, pp 1083-1115. Walker, Douglas, 1983. preliminary report, stratigraphy of the northern Soda Mountains, in Evolution of early Mesozoic tectonostratigraphic environments, southwestern Colorado Plateau to southern Inyo Mountains, Marzolf and Dunne, eds. Field trip guide, Geological Society of America.

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Wright, L.A., R.M. Stewart, T.E. Gay Jr., and G.C. Hazenbush, 1953. Mines and mineral deposits of San Bernardino County, California. California Journal of Mines and Geology, Vol. 49, pp 49-192.