The Benitoite Gem mine - San Benito County, California

By John Veevaert
Benitoite.com
Special Thanks to Scott Werschky & Tomek Praszkier for editing and layout

M. Budil specimen. J. Scovil photo.

2 x 1.6 x 1.1 cm benitoite & Neptunite
John Veevaert Collection

INTRODUCTION

Benitoite almost every mineral

collector desires to have a specimen
of this unique blue mineral. Aside from
3.8 x 2 x 1.4 cm benitoite 4.6 x 3.3 x 3.0 cm benitoite - John Veevaert Collection
a few small nearby deposits, only the
John Veevaert Collection
Benitoite Gem mine has commercially
produced gem quality benitoite and
specimens of stunning beauty. Since its
discovery in 1907, literally tens of thou-
sands of benitoite and neptunite speci-
mens have been produced. It is a slow
and involved process to remove the
encasing natrolite with various chemi-
cals but the effort is well worth it to un-
cover the mineral heritage from one
of the most unique mineral deposits
in the world. The State of California rec-
ognized the significance of this distinc-
tive mineral by declaring it to be the
Official State Gemstone of California. On
October 1, 1985 in Sacramento, Califor-
nia, the State legislature passed Assem-
bly Bill No. 2357. The text was simple,
1.7 cm fully terminated crystal
but it was everything that everyone who John Veevaert Collection
knew anything about benitoite had ever
hoped for. Section 425.3 is added to the 3.8 x 2.7 x 2 cm benitoite - John Veevaert Collection
Government code to read: Benitoite is
the official state gemstone of Califor-
nia.

LOCATION

The Benitoite Gem mine, formerly

known as the Dallas Gem mine, is situ-
ated near the southern tip of San Benito
County about 30 km to the north and
west of Coalinga, California. The town of
King City lies about 45 km to the west of
the mine. In a broader sense the mine
lies about half way between San Fran-
cisco and Los Angeles. The stereotype of
California usually involves visions of
endless beaches, and lots of people. This
section of California however, is consid-
ered remote by just about any standard
imaginable. Few roads and no amenities
that most people are used to can be
found within 30 km in any direction. The 3.8 x 2.2 x 2 cm benitoite & neptunite - John Veevaert Collection
only way to get near the mine, other than
5.5 x 2.2 x 1.7 cm of benitoite etched from crossite included natrolite
John Veevaert Collection
by a privately owned chip sealed road, is
via a bumpy dirt road with several unim- USA Sa Paicines Mendota
Kerman
proved stream crossings. Travel in the nB
winter time is nearly impossible due to
snow and very slick, muddy roads. The en Tranquillity

mine is positioned just upslope of the CANADA ito

San Benito River at an altitude of 1,380 Sa
Gonzales
Co
meters. nF
ra
nc
Ottawa
Soledad
un Benitoite
Canuta Creek

The coastal mountains between San

Francisco and Los Angeles are expan-
Lo co
sA
is

ng USA Washington
t y Gem mine
e les Greenfield
sive and for the most part even today,
empty of any human development other
M
than ranches and a few small towns and EX King City Huron
roads which transect them. Imagine the IC
O Coalinga
difficulty in accessing this region in 1907, San Lucas
Mexico
the year benitoite was discovered, when
20 km
there were no roads and the only means San Ardo Avenal
of moving through the area was on foot. Map of USA with location of the Benitoite Gem mine, and inset showing detail of the mine area.
The vegetation in the area consists of
very thick chaparral that is seemingly when Couch set out, so there was likely cal records suggests that Couch was the persed to universities and mineralogists
impossible to walk through yet that was some cold weather to contend with as sole discoverer of the deposit. around the globe.
the task set in front of James Couch as he made his way into the headwaters It did not take long for the area to Initial recovery of benitoite con-
he left Coalinga to prospect the area in of the San Benito River looking for traces be legally claimed and mining to com- sisted of breaking open the encasing nat-
mence. The claim was given the name rolite by sledge to find the gem nodules.
of Dallas Gem mine in recognition of the
financial backing provided by Dallas
for the operation. Still, none of the char-
acters involved knew what it was that
they were mining. Speculation centered
on the crystals being sapphire or spinel
or even some form of volcanic glass.
Later in 1907 a small group of speci-
mens found their way to Dr. George
Louderback who was professor of
mineralogy at the University of Califor-
nia, Berkeley. Louderback quickly recog-
nized that this blue mineral was new
to science. He also thought that the
accompanying dark black mineral asso-
ciated with the blue mineral, was also
new to science. He set out to publish
a preliminary note in July 1907 on
the new species and tentatively called
the blue mineral benitoite named after
San Benito County and the San Benito
River. He suggested that the black
mineral be named carlosite after the
nearby San Carlos Peak. Later in 1907
Plate from Louderback paper published in 1909. Photo of mine area one year after dis- Louderback determined that carlosite
covery. Arrows shows limit of mineralization. was in fact neptunite a mineral which Photo taken in the Dallas Gem mine in
had been discovered in 1893 in Green- 1907 showing Roderic Dallas (left), first
southern San Benito County for new of minerals eroding out of the adjacent land. owner of the mine, and James Couch
mercury deposits in early February, hills. It is reported in several sources After securing more specimens and (right), discoverer of the deposit. Photo
1907. that he found a forested glade along the having a chance to actually go to the courtesy of Collectors Edge.
small river and made camp after having mine site Louderback commenced to for-
HISTORY OF THE DEPOSIT been prospecting for several weeks. This mally describe the new mineral beni- Perhaps hundreds or even thousands of
offered him a flat place with grass feed toite. Many people consider this one of stunning specimens were lost through
James Marshall Couch had been for his horse, and plenty of firewood for the finest descriptions of a new mineral this method. It did not take long however,
grubstaked by Roderick Dallas and himself to keep warm during the long species ever written. It was published in for the miners to learn that natrolite was
Thomas Sanders with $50 worth of sup- cold nights. 1909 with the chemical analyses being soluble in various acids. It must have
plies and a horse. It was mid-winter Accounts of the discovery report completed by Walter Blasedale. All of the been quite a scene to see hundreds of
that on February 22, 1907 Couch climbed hand-colored copies were quickly dis- kilos of natrolite veins in acid to expose
the hill across from his camp to look
for possible outcrops to investigate.
On his way up the slope he stumbled
upon a small area literally littered with
myriads of small dark blue crystals.
He initially suspected the crystals to
be diamonds or sapphires owing to
the blue color and set about to collect
a small hoard then raced back to
Coalinga to announce his discovery. It
is possible that the Native Ameri-
cans who inhabited this region may have
seen this deposit at some point in the
distant past on a hunting trip but as
far as Couch could tell no one had ever
been to this spot before. Imagine this
outcrop weathering for millennia with
no one knowing of its existence and
then being the first person to have ever
seen this rich blue mineral laying
in abundance on the ground! Credit
for the discovery was taken by other
Mining in the Dallas Gem mine in 1908. people, primarily Roderick Dallas and
Photo was published in Louderbacks another fellow by the name of Leland Cabin at Dallas Gem mine built during the summer 1907 for $35. Mine team with riffles
paper, 1909. Hawkins, but sifting through the histori- and pistols. James Couch is second from the left. Photo courtesy of Collectors Edge.
 group were Pete Bancroft and Ed Swo-
boda who visited the mine several times
between 1935 and 1938 collecting thou-
sands of specimens. In the 1930s it was
still no small task to get to this remote
location. In 1935 they set out to visit the
deposit after having been given direc-
tions to the locality from their high
school teacher, Frank Gulick, who had
actively collected at the deposit the year
before in 1934. For an interesting view of
Entrance to the 50 meters long adit in the mines history, check out the inter-
1908. Note camp dog Fritz. Photo cour- view between Bancroft and Swoboda at:
tesy of Collectors Edge. www.bluecapproductions.com/benitoite.
From the 1940s until 1967 the de-
the enclosed benitoite crystals. Today, posit was leased by several people with
acids and other chemicals are used to varying levels of production. Most no- Stock certificate for 10 shares in the Dallas Mining Company dated on February 1907.
prepare specimens and recover gem tably Miller Hotchkiss in 1952, Clarence Courtesy of Collectors Edge.
rough. However, greater care and effort Cole from 1953 to 1967, and Josephine
are taken to clean aesthetic specimens Scripps, sub-leased from Cole, in 1966. and continued mining operations until has been trucking material from the
by trimming excess matrix and protect- Their efforts were modest in terms of 2000. Frequently seen at the mine was mine to the Los Gatos Community park
ing some of the natrolite which provides overall production. Fresno County Sheriffs Deputy Bob just outside of Coalinga and allowing
a striking contrast with both benitoite In 1967 Elvis Buzz Gray and Bill Kahl. Bob was there to lend some secu- people to screen the material for gem
and neptunite. Forrest leased the property. They were rity to Bill and Buzz and also to help out rough and specimen material. The op-
The Dallas operation of the mine experienced operators and set about as needed. portunity to find specimen material or
went on until 1910. At that time opera- to rehabilitate the mine site and develop In 2001 Gray and Forrest sold
tions ceased and the mine was aban- a logical mining plan for the deposit. the mine to The Collectors Edge of Den-
ver, Colorado. Bryan Lees, the principal
owner of the company, oversaw a com-
plete and thorough mining of the re-
maining deposit. He exposed the original
vein system and found that it had been
completely worked out. His operation
also ran the entire dump material
through a custom jig system to sepa-
rate gem rough. He then set out
to process the colluvial and eluvial ma-
terial that had eroded from the original
deposit over the millennia. A conveyor
belt also carried larger rocks off and
each, while wet, was visually inspected
for specimen potential. His operation
produced many tons of specimen grade
material and thousands of carats of
gem rough. The mine site was completely
rehabilitated according to Surface Professor George Louderback, mineralo-
Mining and Reclamation Act standards gist who did the original descriptive work
in 2004. on benitoites in 1907.
Bryan Lees sold the mine to Dave
Schreiner of Coalinga in 2004. Dave was gem rough at the mine site does not cur-
determined to create a fee dig operation rently exist unless groups access the
there, but has been hindered with mine via the private chip sealed road.
environmental regulations set by the Even then, the previous mining efforts by
Scan of an original copy of Louderback's paper on benitoite. This copy was in the col-
lection of Percy Quensil (quensilite) and is now in the collection of John Veevaert. The Environmental Protection Agency and Collectors Edge left very little material
color plate was hand colored. Bureau of Land Management due to behind.
the presence of naturally occurring Despite the effective mining tech-
doned. Dallas, however, maintained the Their efforts produced thousands of asbestos. Reckless all-terrain vehicle niques used by The Collectors Edge, a
assessment work on the claim and was good specimens and considerable gem and motorcycle operators over the last minor amount of productive material still
able to patent the ground securing per- rough. It was also their effort to promote 50 years have created enormous ero- remains. The mud adhering to much of
manent control over the deposit. From benitoite as a gemstone that raised the sional problems as well, so the agencies the material is tenacious and nearly im-
then until the 1960s the Dallas family awareness such that California desig- established a closure of the area to all possible to remove without repeated wet-
leased to the property to various opera- nated the mineral as the official gem- vehicular traffic allowing access only to ting and abrasion. This masking mud
tors who recovered specimens and gem stone of California in 1985. They bought private property owners and valid claim allowed considerable material to pass
rough. Perhaps most noteworthy of this the mine in 1987 from the Dallas family, holders. For the past several years Dave through the washing system undetected

Stockpile of benitoite-rich natrolite veins at the mine in 1908. At this time etching of
specimens was not use, and not many specimens survived mechanical preparation... Peter Bancroft at the Dallas Gem mine in 1938 with stock of benitoite specimens. Photo
Photo courtesy of Collectors Edge. courtesy of Ed Swoboda.
Workings at the Benitoite Gem mine around 2000. M. Gray photo.

Mine workings in October 2003. J. Bean photo.

Recent satellite image of the mine area

after reclamation. Image bing.com.

primarily of syenitic composition. This

produced numerous calc-silicate vein
systems throughout the district. It was
one of these systems, altering the blue
schist rock, that deposited the min-
eralization found at the Benitoite Gem
mine.

Extended workings at the mine around 2004. Collectors Edge photo. ORIGIN AND STYLE
OF MINERALIZATION

and was eventually used in the reclama- for purchase by collectors to try their of serpentinite which was tectonically The elements that comprise beni-
tion work. Hence, some of this mineral- hand at cleaning their own specimens. emplaced into surrounding sedimentary toite are thought to have been mobilized
ized material will continue to be found Perry and Veevaert are also process- and metamorphic rocks in the Jurassic from the host rock and deposited during
through the action of rain and intense ing material for specimens and gem period. A subsequent plate collision the late stage cooling of hydrothermal
field collector interest. The mine, how- rough. put downward pressure on the serpenti- fluids in calc-silicate veins fracturing
ever, will never again produce at a com- nite. However, being of a lighter density, the wall rock of blue schist blocks. Other
mercial scale. THE GEOLOGY OF THE AREA portions separated and migrated nearby benitoite deposits have a similar
In 2008 John Veevaert of Weaver- upward through the overlying layers setting bearing out the hypothesis.
ville, California (author) and Steve Perry The Benitoite Gem mine is located of rock. This established the foundation Previous geologic investigations have
of Davis, California negotiated purchase in the New Idria mining district situated for a setting where these portions of suggested that the benitoite mineraliza-
of the entire nine-plus ton of inventory of in the southern end of the Diablo Range. serpentinite would experience the low tion was subsequent to the formation
benitoite specimens, partially processed, The district has been prospected since temperature and high pressure meta- of the blueschist. Their analyses place
and unprocessed run-of-mine material the early 1850's for gold, mercury, morphism known as blue schist facies. the age of the blueschist at between 100
from The Collectors Edge. Rough, unfin- chromium, asbestos and mineral speci- During the mid Miocene the region and 160 million years of age and the ben-
ished material has been made available mens. The district covers a large body was intruded by small igneous bodies, itoite present in the cross cutting calc

Unique photo showing benitoite-rich nat-

rolite vein in situ. Collectors Edge photo. Big boulders with natrolite and benitoite veins. M. Gray photo.
 silicate veins at approximately 12 million proposed that color may be due to the
years. All benitoite in situ at the Beni- Fe2+:Ti4+ or the Fe2+:Fe3+ intervalance
toite Gem mine is confined to blueschist charge transfer. Joan Mamarella (per-
blocks altered by hydrothermal veins. sonal communication 1997) suggests
The last phase of mineralization con- in her thesis that the blue color is
sisted of a pulse of natrolite that de- derived from the titanium in the blue
posited within the vein system. The portions of the crystals being paramag-
vein-filling natrolite is found to encase netic while the titanium in the white
most, but not all, of the minerals de- portions are diamagnetic. Benitoite is
posited in the earlier phases. The upper also frequently found as gray to greenish
zone of the Benitoite Gem mine has a colored crystals with very dense inclu-
large concentration of albite veins and is sions of crossite. The vast majority
devoid of natrolite. It is in this upper
zone that rich, deep blue and lustrous
crystals of benitoite were found com-
mingled with milky white albite.
Most of the natrolite veins are less Crystallographic drawings showing the
than 2 cm thick. The minerals of interest various crystal habits and forms of beni-
at the mine are confined to the vein sys- toite. From Louderback, 1909.
tems and frequently are attached to both
vein walls. This creates an obvious prob- came duller due to etching during the
lem during specimen preparation as one natrolite mineralization. The average
side of the vein has to be mechanically crystal sizes for non-included benitoite
removed to permit a chance at produc- is between 0.5 and 1.0 cm. Crystals over
ing a specimen. 2 cm across are considered large and
Though the lower level portions any crystal over 3 cm across is consid-
of the vein system were typically filled
with natrolite, some pockets were left
intact. These pockets typically display Superb, lustrous (probably free growing)
blocky natrolite crystals and in some benitoite crystal, 2.5 cm wide. J. Siger-
cases neptunite and benitoite crystals man specimen. J. Scovil photo.
are still exposed. The size of these pock-
ets is generally quite small, rarely of crossite included crystals are floaters
exceeding 2 cm in size. As mentioned with complete terminations on both
earlier, the upper zone is devoid of ends. Some crystals of benitoite ap-
natrolite. All minerals found in that zone pear red to dark maroon due to inclu-
tend to be hidden only by clay minerals sions of minute neptunite crystals.
which can be easily removed with Pink crystals of benitoite have been
water. Although pocket zones were found at the Mine Numero Uno situated
still not large, and mineralization was several kilometers from the Benitoite
much more scattered in the upper zone, Gem mine. The origin of this color is un-
the crystal quality of benitoite and known.
joaquinite is much higher not having
been subjected to the natrolite-bearing
solutions.

MINERALS FROM
THE BENITOITE GEM MINE
Group of benitoite crystals showing dif-
Benitoite (TL) BaTiSi3O9 ferent forms, size up to 4.5 cm. B. Gray
specimens. J. Scovil photo.
Benitoite is the primary mineral
of interest from this deposit. It is a ring ered to be very large (and exceedingly
silicate and crystallizes in the hexagonal rare). Crystals with crossite inclusions
crystal system. Early in the theoretical can be quite large at up to 5-6 cm across
development of crystallography it was but the crystal form is typically mottled
hypothesized that there was a class in crystals greater than 2-3 cm. 3.1 x 2.5 x 1.5 cm benitoite with the rare
d face pyramid modification. John
of the hexagonal system that would Not all benitoites are the same color.
Veevaert Collection
produce trigonally shaped crystals. The While the more popular color is a rich
discovery of benitoite provided the min- sapphire blue with a hint of violet, beni-
eral world with the first species known toite may also be clear, white, pink, red-
to crystallize in the ditrigonal-dipyrami- dish brown or greenish-gray colors as Benitoite is very strongly dichroic
dal class of the hexagonal crystal well. The origin of the color of benitoite such that when placed in the proper
system. This class is referred to as the has not been completely determined orientation it looks either colorless, blue,
Benitoite Type in Dana. Twinning as of yet. The chemical compound does or rich violet-blue in color. Benitoite has
of benitoite occurs as 180 degree rota- contain traces of iron, hence it has been a high birefringence, higher than that
tion about the c-axis (0001). An equidi-
mensional twinned crystal is referd to as
a "Star of David" owing to its perfect
six sided star. Twinning has only been
found in benitoite crystals included with
crossite. Complete crystals of this form
are very rare.
Benitoite is found in two classes at
the mine as euhedral, floater crystals
heavily included with amphibole miner-
als (commonly referred to as rockies),
and as crystals firmly attached to the
vein walls. It is from rocks of the latter
class that the best gem benitoite has
been recovered. The crystal faces of be-
nitoite were selectively etched during the
natrolite phase of mineralization. Rare
Sequence of photos from start to finish examples of crystals exist with all bril-
of a benitoite & neptunite specimen 7.5 liantly lustrous faces, but in most beni-
cm across. John Veevaert Photos toite the c face and prism faces retained
Bob Schrieber specimen. their luster while the pyramidal faces be- Twinned benitoite up to 3.3 cm across - Buzz Gray specimens, Jeff Scovil Photo
System for washing and sorting gem crystals from dumps. Collectors Edge photo. Buzz Gray operating the washer to remove mud. M. Gray photo.

Bryan Lees watching for specimens and gem rough on conveyor belt. Next step was hand sorting gem crystals and fragments after washing. Last photo shows freshly collected
gem crystals. Collectors Edge photos.

Benitoite gemstones (to 1.66 cts) showing different colors. B. Gray coll. J. Scovil photo. Benitoite gemstones up to 1.43 cts. Collectors Edge specimens. J. Scovil photo.
 of one carat with good clarity and color microscope. Benitoite caused an imme-
will command prices of $3,000 or more. diate sensation with its large well-
Stones of two carats can bring $8,000- formed crystals accompanied by equally
$10,000. Values should continue to striking crystals of neptunite and joa-
appreciate in the future as supply is quinite. There have been few occasions
limited and additional commercial pro- in the history of mineral
duction is not feasible. discoveries where a

Custom benitoite necklace made with

133 gemstones, the largest of which
weighs 3.5 ct. Ed Swoboda collection.
Photo courtesy of Ed Swoboda.

Benitoite crystals with 1.43 ct gemstone. Collectors Edge specimens. J. Scovil photo.
It is hard to new species
rank the finest was found with
specimens but two such magnificent
specimens in the LA crystals.
County Museum are considered to
be among the best a large 3 cm Neptunite
triply terminated crystal and a KNa2Li(Fe2+, Mn2+)2Ti2Si8O24
fabulous ring of adjoined benitoite
crystals. A smaller specimen in the The Benitoite Gem mine has
authors personal collection is consid- produced the worlds finest known crys-
ered one of the finest with the three tals of neptunite. It is by far the most
species benitoite, neptunite and joaqui- abundant mineral aside from Natrolite
nite arranged in an aesthetic position. It in the deposit. Neptunite is about ten
was dubbed the Sushi Plate by Bryan times more plentiful than benitoite.
Lees of Collectors Edge. The principle habit is prismatic though
Most new minerals discovered in some stubby crystals are known. At
the last 100 years have been as a result a macro scale neptunite appears to be
of some unusual diffraction pattern jet black in color. It is actually a deep
in an X-Ray analysis or as some micro- red color which is seen at certain angles
scopic crystals that could only be in large crystals or in micro crystals
Benitoite gemstones up to 5.53 cts. B. Gray specimen. J. Scovil photo. appreciated under a scanning electron where light can pass through it. It also

of diamond. Hence, cut stones come alive

with fire from refracted light. The blue
color of benitoite is not affected by any
treatment such as heat or irradiation, al-
though the colorless sections of a beni-
toite crystal have been changed to
orange when heated (Bill Forrest per-
sonal communication 2002).
Benitoite is strongly reactive under
short wave ultraviolet light radiation.
It fluoresces a very bright, opaque, sky
blue color. The fluorescence appears
to be stronger in crystals with crossite
inclusions than crystals of gem qual-
ity. Some crystals fluoresce a dull red- Gemmy benitoite crystal 8 mm wide.
dish orange color under long wave ultra- AM Mizunaka specimen and photo.
violet light. The strong reaction under
short wave UV light is a very useful at the mine, and for prospecting. The nat-
exploration tool for locating specimens ural fluorescence is also important as it
adds to brilliance of finished gemstones
in sunlight.
The primary use of benitoite is
as specimens for mineral collectors and
use as an ornamental gemstone. Though
not well suited for use in rings due to its
hardness of only 6.5, it is dazzling in pen-
dants, earrings and necklaces. The vast
majority of finished gems are under
0.5 carat weight. Gems over 1 carat are
rare and gems over 2 carats are consid-
ered very rare. The largest known piece
of rough recovered was a 34 carat
piece found by the current owner Dave
Schreiner shortly after he acquired
the mine from The Collectors Edge, Inc.
It produced a finished stone of over
8 carats and several smaller stones.
The largest known faceted benitoite
is owned by Mike Scott and is a 15.42 ct
stone. The prices of finished gemstones
have skyrocketed in recent years. As
a gemstone, benitoite is orders of mag-
Benitoite crystal with gemstones. Collec- nitude scarcer than diamonds, emeralds
tors Edge specimens. Van Pelt photo. or rubies. High quality finished stones Stibiotantalite pendant with benitoites, 4.5 cm high. B. Gray coll. J. Scovil photo.
appears reddish brown in color when
heavily included with crossite. Neptunite
forms two types of twins. The most com-
mon is a twin on (301). The rarest twin
is that found on (001). There are proba-
bly no more than eight or nine of these
known. Crystal sizes for neptunite range
from micros to an average of 2-3 cm.
Crystals as large as 10 cm are known.
Large plates to 1 meter across exist of
neptunite crystals exposed from natro-
lite.

JoaquiniteCe (TL) NaFeBa2Ce2

(Ti,Nb)2[Si4O12]2O2(OH,F)(H2O)

Joaquinite was first discovered at

the Benitoite Gem mine. It is by far the
most complex mineral found in terms of
chemistry. Two other species have been
delineated which include strontiojoa-
quinite and barrio-orthojoaquinite. In the
latter two, niobium and cerium are ab- Photo of giant specimen shown at right. J. Veevaert photo.
sent. The strontium to barium ratios de-
termine which species it is. Most of the vein system and is only rarely encoun-
joaquinite found at the deposit are 3 mm tered in crystals. Where the veins did not
or less in size and have a honey to cin- entirely fill with natrolite, stubby, pris-
namon color. Several crystals are known matic crystals are found. The crystals
to exceed 4 mm. Joaquinite, a monoclinic are invariably milky white and opaque.
mineral, was originally thought to crys- Gray to green colored natrolite crystals
tallize in the orthorhombic system. exist which are heavily included with
However, later work determined that actinolite or crossite. Much of the well
twinning on 001 created the orthorhom- crystallized natrolite in collections la-
bic crystal shape. beled as coming from the Benitoite Gem
mine is in fact from several other nearby
Jonesite (TL) deposits.
Ba4(K,Na)2[Ti4Al2Si10O36]6H2O
Other minerals
Jonesite was discovered in 1957 by
Francis Jones. It was later described in In addition to the above named
1977 as a new species. It is by far the species, the most commonly encountered
rarest mineral found at the deposit. minerals at the Benitoite Gem mine in-
It forms small colorless crystals up to clude the copper sulfides djurleite and
3 mm in length but usually far smaller chalcocite. Other noteable species in-
as single bladed crystals or as sprays. clude: apatite, albite, manganese oxides,
The crystals form in the orthorhombic silica pseudomorphs presumed to be
crystal system. after serandite and analcime. Several
Previous literature suggested that oddities are also known including boatite
jonesite was not found in situ with beni-
toite. It was the view of previous authors
that jonesite formed at the expense
of benitoite since both species contain
barium, titanium and the Si3O9 complex.
The author has several specimens
and knows of others that show a com-
mingling of benitoite and jonesite
together. So their emplacement in the
vein system appears to have been con-
current.

Natrolite Na2Al2Si3O102H2O

Natrolite is ubiquitous throughout

much of the deposit. It was deposited in
Gemmy floater benitoite 1.4 cm wide.
the last pulse of mineralization in the R. Kennedy specimen. J. Scovil photo.

21 cm wide specimen covered by benitoites. Crystal Classics specimen and photo.

 Benitoite & Joaquinite specimen 7.5 cm across.
John Veevaert photo, Spirifer Minerals specimen.

Exceptionally large specimen of benitoite and neptunite,

43 cm wide, printed life-size. Collectors Edge specimen.
J. Wheeler photo.
 Gem benitoite crystals, 2.3 cm wide. Col-
lectors Edge specimen. J. Scovil photo

The Wreath, one of the best known benitoite specimens, 6 cm wide. Natural History
Museum of Los Angeles County specimen. H. and E. Van Pelt photo.
Benitoite crystals to 3.4 cm. Mineral Benitoite, specimen 2.1 cm high. R. Ken-
Search specimen. J. Scovil photo. nedy specimen. J. Scovil photo.

Benitoite specimen, 3.5 cm wide. K. Ward Gemmy benitoites, 4.7 cm wide. B. Gray
specimen. J. Budd photo. specimen. J. Scovil photo.

The famous Josie Scripps benitoite, 18 cm wide. W. Larson specimen.

Gemmy benitoites, specimen 15.5 cm wide. W. Larson coll. W. Minorotkul photo.

Benitoite specimen, 4 cm wide. S. Rudolph specimen. J. Budd photo.

Benitoite crystals to 2.1 cm. B. and E. Moller specimen. J. Scovil photo. Benitoite with neptunite combinations to 6.2 cm. B. Gray specimens. J. Scovil photo.
Neptunites with benitoites and joaquinites, specimen 8.4 cm wide. California State
Benitoite (1.2 cm wide) with neptunite and natrolite. M. Chinellato specimen and photo.
Mining and Minerals Museum specimen. J. Scovil photo.

Superb specimen with benitoite and a 4.3 cm doubly terminated neptunite. Specimen
10.1 cm wide. J. Veevaert specimen and photo.
The famous Sushi Plate with benitoite, neptunite and superb twinned joaquinite.
Specimen 4 cm wide. J. Veevaert specimen. J. Scovil photo.

Benitoite with neptunite, 6.8 cm wide.

Mineral Search specimen. J. Scovil 3.2 cm specimen of benitoite & neptunite.
photo. John Veevaert photo, S. Karseboom speci-
men.

Benitoite with large neptunite crystals, specimen 13.6 cm high. J Gibbs specimen.
30 cm wide specimen with benitoite and neptunite. A. Giazotto specimen and photo. J. Scovil photo.
 Neptunite, 9.5 cm high. D. and M. Bristol Neptunite crystals, 2.8 cm wide. Arken-
specimen. J. Budd photo. stone specimen. J. Scovil photo.

Neptunite crystals with the more com-

mon (301) twinning. Specimens to
Neptunite twinned on (301), 3.4 cm high. 6.8 cm. B. Gray specimens. J. Scovil
M. Gray specimen. J. Scovil photo. photo.

Neptunite crystals with natrolite, 6.3 cm wide. F. Benjamin specimen. J. Scovil photo.

Neptunite twinned on (301), 2.8 cm wide. W. Larson specimen. J. Scovil photo.

Gem neptunite crystal 0.9 mm high on

Neptunite exhibiting rare twinning habit benitoite. L. Mattei specimen and photo.
on (001). The twin is 2.3 cm across. John
Veevaert specimen & photo. 12.5 cm specimen of neptunite on crossite. John Veevaert photo, Marty Zinn specimen.

Neptunite, specimen 6 cm high. J. Rosen- Neptunite, 3.7 cm high. J. Rosenthal Roderic and Lyda Dallas donating a huge neptunite specimen to the University of Cali-
thal specimen. J. Scovil photo. specimen. J. Scovil photo. fornia at Berkeley, ca 1940s. Photo in courtesy Collectors Edge.
 Apatite crystals to 4 mm in natrolite. Jonesite crystal cluster, 1.2 mm wide. Jonesite crystal cluster, 4 mm wide. Natrolite crystals to 1.9 cm. J. Veevaert
J. Veevaert specimen and photo. C. Rewitzer specimen and photo. J. Veevaert specimen and photo. specimen and photo.

Joaquinite with benitoite. Field of view Joaquinite crystal, 2 mm long. C. Rewitzer Joaquinite crystal, 0.9 mm wide. C. Rewit- Joaquinite crystal, 1 mm tall. E. Lackner
3 cm. B. Gray specimen. J. Scovil photo. specimen and photo. zer specimen and photo. specimen and photo.

moved it cannot be put back. Too much specimens command large prices. They
removal is as detrimental to the finished are, unfortunately, the exception to the
specimen as leaving too much. Several rule.
steps including the application of an
etch inhibitor, soaking in acid, and rins- ACKNOWLEDGMENTS
ing are necessary to remove enough
of the natrolite so as to present The Author would like to thank
an aesthetic specimen. More infor- the following people for their con-
mation on how to clean speci- tributions to this paper: Pete
mens from this deposit can be Bancroft, Ed and Bryan Swo-
found at www.benitoite.com. boda, Buzz and Mike Gray,
A final word here on Bill Forrest, Bob Kahl,
Djurleite crystal with benitoite. Crystal Djurleite crystal with benitoite. Crystal benitoite from the Beni- Steve Perry, Rick Kennedy,
size 0.7 mm. J. Veevaert specimen and size 0.8 mm. J. Veevaert specimen and toite Gem Mine. It is esti- Rock Currier, Chris-
photo. photo. mated that at least 98% tian Rewitzer, Jesse
of all benitoite crys- Fisher, Bryan Lees
was focused primarily on the recovery tals have a matted and Richard Jack-
of gem rough. This resulted in count- luster. The pina- son of the Collec-
less quantities of specimens that were coid and prism tors Edge, Tony
battered and not suitable for collec- faces will al- Peterson, the
tions. Once the use of acids was em- most always L. A. County
ployed to remove the natrolite the qual- be lustrous. Museum of
ity of specimens increased exponen- The pyra- Natural
tially. midal faces, H i s t o r y,
So, what does it take to get a however, will Elmar Lack-
cleaned specimen of benitoite and/or not. That is just ner, Harold and
neptunite? Attractive specimens of this the way Mother Faceted benitoite broche in the shape of Erica Van Pelt,
1.2 mm djurleite crystal with neptunite. beautiful mineral assemblage just don't Nature created a benitoite crystal, 5.7 cm wide. Luigi Mattei, AM
C. Rewitzer specimen and photo. happen they are the result of many these things. Com- M. Gray specimen. J. Scovil photo. Mizunaka, Joan
hours spent carefully removing the en- pletely lustrous Mamarella, Jeff
and a unique specimen of wire silver ex- casing natrolite to provide an aesthetic crystals are rare. The other thing to re- Scovil, Henry Barwood, Joe Budd, Mat-
solved from a djurleite crystal. finished specimen. The process involves member is when something has sat teo Chinellato and special thanks to
several steps all of which are time con- around for millions of years some frac- Wendell Wilson.
SPECIMENS suming and require a bit of artistic apti- turing is likely to occur. The vast
tude. One thing to keep in mind during majority benitoite crystals were frac- John VEEVaERt
Most of the early efforts to recover the process is that removing matrix tured though eons of natural processes. trinity Minerals, USa
benitoite was done mechanically and is a one way procedure. Once it is re- That is why the best quality benitoite e-mail: john@trinityminerals.com

Benitoite & Neptunite specimens from the Collection of John Veevaert