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The February Meeting
by Jake Slagle
Our meeting for February 25th will be given by Jake
Slagle. He will discuss and show images of Maryland
collected minerals that are owned by the Harvard Natural History Museum, Minerals collected in Delaware and Worldwide Classic Treasures that are on display at the
Delaware Mineralogical Museum.
We’ll meet as usual at the Natural History Society of
Maryland, 6908 Belair Road, Baltimore, Maryland. The
meeting will begin at 7:30 pm. If you need directions,
just go to our website. Refreshments will be “catered” by
Steve and Carolyn Weinberger.
Please note that we still need hosts for the April and
October meetings. Please let Jim Hooper know if you can
fill the void.
Inclement Weather Policy
Earth’s (Really) Most Abundant Mineral
by Al Pribula
Quick: What is earth’s most abundant mineral? Do
you think it’s calcite (i.e., limestone)? Maybe quartz? Perhaps something in the feldspar group? Hmmm…surely,
it must be some sort of silicate. Wait a minute! I read
my January Conglomerate! It’s ice! Well…ice may be the
most abundant mineral on the surface of the earth, but
what about the earth itself? There’s a lot more to the
earth than just its surface (crust). Give up yet?
It’s bridgmanite! Huh? Never heard of that mineral? Don’t have a specimen of it in your collection? Haven’t seen
it on eBay, at a mineral show, on a mineral dealer’s website,
or even in a museum? Can’t find it in the latest edition of
Fleischer’s Glossary? Well…don’t feel too bad. Until a couple of years ago, no one else had seen it, either, at least not
as a natural sample. But (you ask) if it’s the most abundant
mineral, how could it have remained unseen for so long?
This mineral is believed to make up about 38% of the
earth’s total volume, representing about 93% of the mantle
of the earth. That’s right—the mantle, the layer between the
crust and the core, which has never been directly sampled or
observed. In 1962, it was hypothesized that the lower mantle
at depths of 400-1800 miles consisted primarily of a high-density form of magnesium-iron silicate with the chemical formula
(Mg,Fe)SiO3 crystallizing in the perovskite structure. (It would
be dimorphous with akimotoite, another high-pressure mineral.) Knowing the properties of this “silicate perovskite” would
add to our understanding of material and heat transfer within
the earth. Its properties were studied indirectly by measuring
changes in earthquake waves as they travel through the earth,
and high-pressure studies had been performed on synthetic
samples. However, since a natural (i.e., non-synthetic) sample
of the material had never been observed or studied, it could
not be submitted to the IMA Nomenclature Committee to
continued on page 5
Baltimore Mineral Society
The BMS was established in order to allow
its members the opportunity to promote
the study of mineralogy and to act as a
source of information and inspiration for
the mineral collector. We are members
of the Eastern Federation of Mineralogical
Societies and affiliated with the American
Federation of Mineralogical Societies.
Meetings are held the 4th Wednesday of
each month (except November,, December, June & August) at the Natural HIstory
Society of Maryland beginning at 7:30 p.m.
Visit the club website <www.baltimoremineralsociety.com> for directions.
Yearly dues are $10 for individual members and $15 for family memberships.
Send payment along with your name, list
of family members, if applicable, address,
phone and e-mail to: BMS, PO Box 302;
Glyndon, MD 21071-0302.
Officers:
President................................Jim Hooper
<ijhooper at jhu.edu>
Vice President............. Alice Cherbonnier
<alicecherbonnier at gmail.com>
Secretary.................................Jake Slagle
<jake at marylandminerals.com>
Treasurer ................. Carolyn Weinberger
<cscrystals2 at gmail.com>
Directors:
Conference Chair
Bernie Emery
Al Pribula
Steve Weinberger
Mike Seeds
President’s Postings
by Jim Hooper, BMS President
Here we are at the end of February; the shortest month of the year and one that often feels like
the longest. Hopefully the worst of winter weather
is behind us and we can better enjoy the longer
days of light. Next month comes the Vernal Equinox
and official Spring. Time to think about getting out
and about for more hunting and collecting. In connection with that let me urge everyone who is interested in clubsponsored field trips to contact Bob Eberle and let him know that you want to
participate. He needs names and numbers to assure quarry managers that we
can furnish enough people to have them open their gates to us on a weekend.
He has ideas and has made some contacts with sites and I will leave details to
him to announce. Collecting trips are fun and amazing even if you don’t find a
museum piece. At the same time they are dangerous environments and safety
and looking out for one another are taken very seriously. Proper equipment is
required and respect for the site owners rules are essential to let them know
we are responsible and worth inviting back. Last year we invited members of
the Chesapeake Gem and Mineral Society to join us on trips. I’d like to see the
invitation extended this year as well. Better numbers of participants could show
site owners that it’s worthwhile to let us in on their days off. The annual gala rock, mineral, gem, fossil exposition in Tucson, Arizona took
place earlier this month and I’m sure we can count on excellent verbal and visual reports from BMS attendees on the sights and wonders found there at the
meeting and later on this year.
It appears we need to encourage more participation in providing or ‘hosting’ the monthly BMS meeting with snacks and beverages. We can take it up in
discussion at the meeting to see how to spread that out among the membership
a little more. I think as we welcome more members to the society we can think
of having more than one member shoulder the responsibility and maybe have 2
or more members plan to spread out or share bringing snacks to a meeting. We
should avoid it becoming a burden for a few hearty souls to take care of. I’d like
to hear ideas at the meeting.
Editor.....................................Mike Seeds
<mseeds at fandm.edu>
March is almost here and often a month with surprises in weather from
nice, sunny days to getting an occasional foot of snow or layer of ice. Be careful
out there. I look forward to seeing you at the meeting.
Write for “The Conglomerate”!
Send news, announcements, comments,
observations, or articles to <mseeds at
fandm.edu>. No e-mail? Hand in your submission at a meeting.
PS – the birthstone for February is Amethyst.
Jim
Non-commercial reprint
permission granted to
non-profit organizations
unless otherwise noted.
2 Page
The Conglomerate –February, 2015
Minutes From our Last Meeting
Upcoming Collecting Trips
meeting on March 27-29 in Hickory, NC in conjunction
with a gem and mineral show taking place there. Noting
that BMS was entitled to two votes, she encouraged members to consider attending. She also mentioned that the
aforementioned affair would include a field trip to the Reel
Amethyst Mine. She requested that anyone interested in
attending and representing the club at the meeting should
let President Jim Hooper know as soon as possible.
by Jake Slagle, Secretary
President Jim Hooper called the January 28th meeting
to order at 7:45 p.m. and noted
that this evening marked a notable anniversary: a full year of
meeting at the Natural History
Society of Maryland. Minutes
of the previous meeting as
shown in The Conglomerate
were accepted by consensus.
Two guests were introduced
named Andrea and Rick.
Treasurer Carolyn Weinberger noted that the Society was solvent and also that it
was time for dues to be paid. Carolyn also called attention
to the recently revised Mindat site where Baltimore Mineral Society was named as a contributor.
Field Trips: The field trip chairman was not present to
give a report. However, discussion ensued regarding issues
relating to field trips. They included mention by Carolyn that
field trips were the primary reason for some to be members
of BMS. Further discussion related to very poor attendance
on two recent field trips as well as a failure to disseminate
essential information about them in advance both in the
Conglomerate and via e-mail to their taking place.
Mineral of the Month: The mineral of the month for
this January was millerite. A diversity of specimens was
shown as provided and briefly commented on by Al Pribula, Steve Weinberger, and Jake Slagle.
Unfinished Business: It was noted that there were still
two months available for members to volunteer to bring
snacks for the meetings.
Announcements:
Web Site: Brad Grant announced that BMS was turning to a different company for its web hosting and web
design needs. He indicated that he expected work on the
revised site would be complete by Spring. EFMLS: Jim Hooper inquired about the availability of
borrowing programs from the EFMLS library. It was noted
that the available programs are listed in the EFMLS Directory which the President received last March. Carolyn advised that EFMLS was holding its annual
The Conglomerate –February, 2015
by Bob Eberle
Small Wonders Micromount Calendar: Steve Weinberger held up a “Small Wonders” micromount calendar
and noted that its credits included information relating to
the importance of the Baltimore Mineral Society and its
Annual Micromount Symposium to the pursuit of micromounting.
Alice Cherbonnier brought a quantity of postcards relating to Kentucky agate advertising a well illustrated book
about this intriguing agate variety.
Bernie Emery announced that the Chesapeake Gem
and Mineral Show would be held on Saturday, April 30,
2015 at the Ruhl Armory in Towson. With no further business or announcements, the
meeting adjourned at 8:15 p.m. and was followed by a well
received slide presentation given by Alice Cherbonnier featuring the Harvard Museum of Natural History.
Submitted by,
Jake Slagle: Secretary
Last Call!
Just a quick reminder that
renewal of your membership
in BMS for 2015 is supposed
to be done by the February
meeting. If you’ve not yet
renewed, please complete the form attached to this issue
and either give it to Ye Olde Treasurer at the upcoming
meeting or mail it to the address shown on the form.
Dues remain at $10 per individual or $15 per couple
and children under age 18.
Page 3
Mineral of the Month – Pegmatitic Minerals
by Steve Weinberger
This month we will be looking at minerals formed within
pegmatites. Pegmatites are usually coarsely grained granitic
magmas that contain a number of minerals. Among these
are feldspar, quartz, mica, tourmaline, beryl and topaz
among other rare element minerals.
New Book Highlights Beautiful Agates from
Kentucky
by Alice Cherbonnier
Cavities in the pegmatites can be lined with excellent
examples of these minerals. Ore veins can also be found
and these can include metallic elements such as copper,
gold, silver, zinc, lead, etc.
Let’s look at three of the above-mentioned minerals. Beryl and tourmaline both have hexagonal crystal systems, while
topaz is orthorhombic. All three of them are gemstones and
can be cut and polished relatively easily, although topaz can
cause problems because of its cleavage planes.
Colors of the three have great variety. Beryl can
be green (emerald), blue
(aquamarine), pink (morganite), yellow (golden beryl), or colorless (goshenite.)
Tourmaline can be black
(schorl), brown (dravite),
red (rubellite), colorless
(achroite), or blue (indicolite.) Topaz can be colorless,
blue, yellow, brown-orange,
pink or violet pink.
Beryl var. Morganite
Oceanview Mine
Pala, Pala District
San Diego Co. CA
Because of the optical
properties such as refraction, clarity and colors, all
three are used frequently as
gemstones. Their hardnesses are 7 1/2 —8 on the Mohs
scale which makes them ideal for use in jewelry because
they are hard enough to resist wear but not too hard to
cut. Although their costs are not in the range of diamond
and fine ruby, topaz and beryl are well above gems such as
quartz (amethyst and citrine.) Fine emeralds can demand
very high prices, though.
Bring in some of your best examples of these pegmatite minerals to supplement this month’s talk.
Page 4
The University Press of Kentucky has published Kentucky Agate, a hardback book that showcases hundreds
of photographs of the vibrant fine-grained agates to be
found in the state’s Knobs Region, near West Virginia and
Virginia. These agates, as the book reveals, can be exceptionally beautiful and intensely colored. In addition to explaining the finer points about agates, the book includes
maps that will guide field collectors to sites where these
agates can be found.
Kentucky Agate, written by Roland L. McIntosh and
Warren H. Anderson, is available in hardcover for $45. It
may be ordered online at www.kentuckypress.com, or call
1-800-537-5487. If you mention the Offer Code FKAG, you
will receive a 25% discount, according to the publisher’s
announcement. Shipping in the U.S. is $5 for the first book
and $2 for each additional book. Kentucky Agate is also offered as an e-book.
Interested in Field Trips?
Please contact Field Trip coordinator Bob Eberle and let him know so he can
make a list of club members who
are likely to come on a field trip.
Contact Bob at <rae2412 at gmail.com>
The Conglomerate –February, 2015
Most Abundant Mineral
continued from page 1
give the mineral an “official” name.
Enter a team scientists headed by Oliver Tschauner from
the University of Nevada at Las Vegas and Chi Ma at CalTech. They reasoned that if this mineral phase was only stable under
conditions of high pressure and temperature (it’s believed that
the pressure in the mantle is about 240,000 times the pressure
at the surface of the earth, at a temperature of about 2000ºC
(3700ºF)), then it could have formed at the earth’s surface as a
result of the high temperatures and pressures created by a meteorite impact and then “frozen” when the meteorite cooled
suddenly. In 1969, a high-pressure form of olivine (the mineral
Gus’s Magic Face
by Mike Seeds
A few weeks ago Pudge and the quarry owners pretty
daughter drove down to Gringotts Farm to talk to old Mrs. Gringotts. They spent two hours drinking weak tea and eating rockhard butter-beer scones, but they convinced her to let the club
collect on the old mine tailings at the back of her farm. The next
Saturday morning, 8 cars managed to make it over the rocks
and potholes of Hedwig Road to the mine tailings.
By lunch, most club members had left, but Gus, Eddie,
Pudge, and Slick decided to spend the afternoon. Unfortunately they hadn’t brought lunch. The quarry owners pretty
daughter was packing up her Jeep to go home and attend a
bridal shower for the Diagon triplets, Loraine, Laraine, and
Alley, when Gus suggested he ride into Snapetown with
her and get sandwiches at Weasley’s Deli. “It’s only a 15
minute ride each way and I can hitchhike back. I’ve got a
good hitchhikers face.”
An hour and a half later, Gus staggered into the collecting
site with a sack of sandwiches. He slammed his hat on the
ground, “What the (bleep) is the matter with these (bleep)
people,” he complained. “No one would pick me up.”
Pudge laughed. “Maybe your hitchhiker’s face wasn’t
working its magic.
Eddie was jabbing a short stick at a hole he was digging. “It’s a good thing you didn’t walk both ways, Gus. It
would have taken you two and a half hours.”
Problem: How did Eddie figure that out so fast?
Solution on page 11.
The Conglomerate –February, 2015
ringwoodite) was discovered in the Tenham meteorite (an L6
chondrite which was the first meteorite fall confirmed in Australia (Queensland, 1879)), and this meteorite is also the “type
locality” for akimotoite (1997), so they reasoned that might be
a good place to search for “silicate perovskite” as well. Previous studies on other meteorites had used high-energy electron beams, but these were powerful enough that any of this
substance which might have been present would have been
decomposed. Therefore, to do their search, they used X-ray
crystallography (which is less energetic than electron beams)
to determine the structure, and electron microprobe analysis
to determine the composition. Since the grains of “silicate
perovskite” they found ended up being smaller than 1 micrometre (.00004 in), and are very sparsely scattered throughout the sample, a special micro-focusing apparatus had to be
used. It took about five years of painstaking collection of data
using these techniques to convince them that they had indeed
confirmed the presence of this high-pressure mineral.
Once they were convinced, they submitted their evidence to the IMA Nomenclature Committee, which approved
the name bridgmanite on June 2, 2014 (it’s IMA 2014-017;
type specimen is USNM 7703 in the Smithsonian collection),
and their results were published in the November 28, 2014
issue of the journal Science. The name was chosen in honor
of Percy Williams Bridgman, who received the Nobel Prize in
Physics in 1946 for his pioneering studies of materials (especially minerals) under extremely high pressures. The natural
sample had a slightly different composition than the synthetic
ones (more iron in its +3 state, along with some sodium), giving them a better “model” to use in studies of the properties
of the mantle. Some scientists believe that some inclusions
in/on diamonds are marks left on them when bridgmanite
from deep in the mantle changed to its low-pressure form
during the diamond’s trip from the mantle through the crust.
So…the earth’s most abundant mineral now has an
“official” name. (Unfortunately for Micromounter’s Hall
of Fame member John Ebner, who collects mounts of
minerals prepared by the person for whom the mineral is
named, he won’t be able to add this one to his collection,
since Bridgman passed away in 1961.) (Note: even though you can’t buy a specimen of bridgmanite per se on eBay, it is possible to purchase small bits
of the Tenham meteorite from sellers there. Might one of
these fragments contain some bridgmanite grains? Guess
you’d just have to study them the same way Tschauner, et
al. did to find out!)
Page 5
Crystals of Water Falling Gently
by Ed Goldberg. Photos from <www.its.caltech.edu/~atomic/snowcrystals> used courtesy of Ken Libbrecht.
President Hooper’s riddle (“Mystery Mineral” page 3,
January Conglomerate) reminded me that my last mineral
field trip was shoveling the driveway this week. In doing so,
I must have mangled about 1x10 (exponential) beautiful
crystals, of the kind that are featured in The Snowflake (by
Caltech physics prof Kenneth Libbrecht, Voyageur Press), a
copy of which Jim owns.
A typical snowflake
The micromounting of
snowflakes is not recommended, however, unless you do
so inside an icy meat locker.
But the crystallography of ice
is even more subtly beautiful
than we usually credit, and Dr.
Libbrecht’s book demonstrates
that amply and vividly.
The overall structure and the tiniest details in a snow crystal
depend on the conditions in which it formed and its history as
it fell to Earth.
We’ve just lived through the 2014 International Year of
Crystallography. (No group more than the BMS should have
been aware of that.) It also happens to be about 400 years
since pioneering astronomer Johannes Kepler observed the
symmetry of ice crystals while on his way to a New Year’s
Eve party in Prague, while crossing the Karlsbrucke (Charles
Bridge) (Vardiman, Larry,Microscopic Masterpieces: Discovering Design in Snow Crystals, Institute for Creation Research 2015). Kepler published the results of his study in A
New Year’s Gift, or On the Six-Cornered Snowflake .
Not all snowflakes are six-sided platelets
The principle known to micromounters is that even
the smallest, simplest things of nature endlessly fascinate.
That applies 6-fold to the most important molecule in the
universe, the dihydride of oxygen, which so nicely finishes
off that splash of bourbon at the end of the workday.
Another is the variation-on-a-theme character of a
mineral’s crystals, which appear in a panoply of crystal
habits, but all of whom obey invariable laws of geometry,
and which are attributable to factors of temperature and
pressure and other environmental conditions at the time
of formation. But no substance appears to be as versatile
in this regard as water ice.
Page 6
Kepler lacked even the most rudimentary magnification devices when making
his studies. Researchers in
our own time have had access, of course, to powerful
tools in their analyses. Explanations for the variety
of snow crystal forms have
focused on the temperature
conditions of the water vaHexagonal symmetry dominates por molecules surrounding
the seed crystal when they
nearly all snow crystals no matter what their history.
become fixed. As temperatures below 0 C decline, crystals will favor thin needles or columns, then plates, then
dendrites. (See, e.g., Furukawa and Wettlaufer, “Snow and
Ice Crystals”, Physics Today (Dec.2007); and Hallet and Mason, “The influence of temperature and supersaturation
on the habit of ice crystals grown from the vapour”, Proc.
Royal Society of London, 1958).
The Conglomerate –February, 2015
Native Elements – Gold
by Al Pribula
Of all the native elements (especially the metals), gold
the circle was considered to be the most symmetrical and
is among most collectors’ favorites, if not the favorite. Due
“perfect” of all shapes. It was considered to be the “king”
to its distinct color (it’s the only yellow metal—almost all
of metals, and one of the few chemical solutions known to
the others are gray or silver-colored), durability (it’s the
dissolve gold is called aqua regia –“royal water.”
least chemically reactive of all the metals, so it doesn’t corrode or tarnish read Mineralogically, gold is interesting due
ily), and workability (its malleability and
to its crystal form and its widespread disrelatively low melting point make it easy
tribution. It is element number 79 in the
to work into a variety of shapes), gold
chemist’s periodic table, and is found in
has been valued highly by most cultures
the same group as copper and silver bethroughout history. It is the stuff of legcause it shares some chemical similariends, poetry, operas, and empires. It is a
ties with them. Due to the relatively low
nearly universal currency, held by many
chemical reactivity of these elements,
people (and governments) as an investmany cultures have used them in applicament. It is mentioned over 450 times
tions in which durability is desired, includin the Bible. It has come to mean the
ing in coins, so they are referred to as the
best possible (“gold standard,” “golden
coinage metals. Mineralogically, these
boy,” “golden age,” “golden rule,” “gold
three elements (along with lead, which
medal,” etc.). The search (in the end, a
is chemically very different but similar in
fruitless one) for the method of turning
structure) comprise the “Gold Group.” It
Gold
base metals into gold was one goal which
is soft (hardness 2½-3), relatively lowRosja Montanӑ
drove the alchemists, forming the basis
melting (1063ºC; 1945ºF), and very dense
Alba Co. Romania
for modern chemistry. It has been used
(specific gravity of 19.3 when pure, but
for decorative objects since at least the 10th century BCE
can be as low as 15 due to impurities). Its concentration in
and for coins since at least 550 BCE. The search for gold
the earth’s crust is about 1 part per million. In the oceans,
spurred the exploration (and exploitation) of this hemiits concentration is about 10 parts per trillion, and it is essphere and other parts of the world, and empires rose and
timated that the gold in the oceans would be worth about
fell due to the search for this yellow metal. It has been
$1500 trillion if it could be extracted economically (which
said that the history of gold is the history of the world. Just
it can’t with current technology). It is ductile enough that
what is this stuff, anyway?
a 1-gram (.035-oz) piece can be drawn into a wire 160 meters (525 feet) long, and malleable enough (it is the most
The word “gold” probably stems from the Anglo-Saxon
malleable of all metals) that it can be pounded into sheets
word geolo, meaning “yellow.” Its chemical symbol is Au,
as thin as .00014 mm (.0000055 in), corresponding to fewwhich derives from the Latin name aurum, meaning “glow
er than 1000 atoms thick, which are so thin as to be transof sunrise.” In other languages, its name is often some
parent.
variation on the Latin name (such as oro (Spanish, Italian,
Esperanto), or (French), ouro (Portuguese), aur (Romanian,
Crystallographically, gold is in the isometric crystal
Welsh)) or on the English name (gold (German), guld (Dansystem, hexoctahedral class, with the atoms packed in a
ish, Swedish), goud (Dutch), gull (Icelandic, Norwegian),
face-centered (cubic closest-packed) lattice. Minerals in
kuld (Estonian), kulta (Finnish)), but is chryso in Greek,
this class form very symmetrical crystals (this class has the
złota in Polish, and zlato in Czech and Slovak. It is one of the
highest symmetry of any of the crystal classes), and gold
dozen or so chemical elements known to the ancients (i.e.,
crystals can show cube, dodecahedron, tetrahexahedron,
before the Middle Ages). Because of its color, it historically
or (most commonly) octahedron faces. Its crystals tend
was associated with the sun, the most important object in
to be very small and often distorted or showing hoppered
the sky, and the alchemical symbol for gold () was the
faces. It can also form twins according to the spinel twin
same as that for the sun. The Incas called gold “the sweat
law. Groups of arborescent or dendritic crystals make
of the sun.” Due to its resistance to tarnishing or corrodcontinued on page 8
ing, gold was considered to be the “perfect” metal, just as
The Conglomerate –February, 2015
Page 7
Gold
continued from page 7
beautiful (if expensive) specimens. Most commonly, it is
found as plates or sheets (often showing triangular markings or hillocks), flakes, nuggets, wires, spongy masses, or
grains, either in matrix or in placer deposits. The initial formation of native gold is in matrix (often quartz, often with
pyrite and other sulfides). Because the gold is less chemically reactive than the host rock, when weathering occurs,
the less-resistant rock weathers first, and the gold is released, allowing it to concentrate with the smaller pieces
of rock formed. As these wash into streams, the gold is
further concentrated due to its high specific gravity. Panning of this sand/gravel/sediment takes advantage of its
high specific gravity, allowing the gold to be concentrated
at the bottom of the miner’s gold pan or sluice box. This
so-called alluvial or placer gold can be found in all particle
sizes from very tiny (“flour gold”) through fist-size and larger nuggets. (The largest nugget ever found came from Victoria, Australia, and weighed 112 kg (246 lb).) Since gold
is very soft, and it is tumbled by the action of the stream,
samples from placer deposits very rarely show any identifiable crystal faces. Commercially, gold is extracted from
the crushed host rock by amalgamation with mercury or
dissolved in a cyanide-containing solution and then precipitated with zinc or recovered by electrolysis.
When found in its native state, it is relatively rare for
gold to be extremely pure. It usually contains 5-20% silver,
and often traces of iron, copper, bismuth, mercury, tin, zinc,
arsenic, antimony, or the platinum-group metals. Natural
alloys of silver and gold are called electrum. (“Officially,” to
be called electrum, the silver content should be above 20%
by weight, but I have heard this term used for samples with
much lower silver content.) In addition to “pure” gold, it
is found “native” as the intermetallic compounds anyuiite
(Au(Pb,Sn)2), auricupride (Cu3Au), hunchunite (Au2Pb),
maldonite (Au2Bi), tetra-auricupride (AuCu), yuanjiangite
(AuSn), and a few others, as well as native alloys such as
electrum and porpezite (palladian gold). (Nomenclature
note: An intermetallic compound has a more-or-less fixed
ratio by weight of its components and hence a fixed chemical formula. An alloy is a mixture of two or more metals
in variable proportion by weight, so doesn’t have a unique
chemical formula. Most naturally-occurring alloys are not
given their own mineralogical name, but are referred to by
hybrid names such as mercurian gold, cuprian gold, etc.) In addition to being found “native,” it is also found in the
telluride minerals petzite (Ag3AuTe2), sylvanite ((Ag,Au)
Te2), and calaverite (AuTe2). When these are heated, the
Page 8
tellurium is driven off, leaving the metal behind. Many
specimens of “native gold” were originally specimens of
one of these minerals which were “roasted” to leave the
gold or electrum behind, often as a pseudomorph of the
original mineral.
Most of the uses of gold are a result of its chemical
inertness. When making jewelry, coins, dental fillings, or
electrical connections (as in computers and cell phones),
the last thing that you want is for the metal to corrode, oxidize, or tarnish! Historically, most gold has been used for
coinage, jewelry, or for decorative purposes (often ecclesiastical (think golden chalices), ceremonial and symbolic
(think the golden spike or gold wedding rings), or honorary (think gold medals)). In many cultures (particularly
nomadic ones), it has been used in a “show-off” way to
indicate wealth and/or status. (For example, having your
guests eat their meal using tableware made of gold is pretty “show-offy.”) Since pure (24-karat) gold is extremely
soft, in applications such as coinage, vessels, dental fillings,
and jewelry, it is always alloyed with one or more other
metals (most frequently copper) to harden it. Depending on the metal used along with the gold, different colors
can be obtained. “Rose” gold contains copper and a bit
of silver; “green” gold contains copper and cadmium (and
sometimes silver); “white” gold contains nickel, manganese, or palladium; iron or indium gives gold a bluish color,
and aluminum gives it a purplish color. It is used to form
a transparent heat-reflecting coating on glass, and it is responsible for the color in “ruby” glass. If all the gold ever
mined were to be brought together and melted into one
sample, it would occupy a volume of about 300,000 cubic feet—enough to cover a US football field (including the
end zones) to a depth of less than 5½ feet. But, because
of its high specific gravity, that “nugget” would weigh over
190,000 tons! About 90% of that total has been produced
since 1910, with about 65% since 1950, and current worldwide production is about 2500 tons annually.
Native gold is found in many localities worldwide, but
never in great abundance at any of them. (In my collection, I have gold specimens (mostly small placer nuggets—
college professors (especially retired ones) aren’t that
affluent!) from more than 225 localities.) In the US, it is
found in “large” quantities in AK, CA, NV, and CO, but has
been commercially mined (usually not in its native form) in
continued on page 9
The Conglomerate –February, 2015
Shoebox Adventures: Cheap Treasure
Beautiful mineral specimens are nature’s treasures,
and some of the best are combos – one mineral growing
on another. The mineral magazines and web sites are filled
with photos of such gorgeous formations. We see amazonite on smoky quartz and wulfenite on calcite. Unfortunately these combo specimens are expensive; people pay tens
or even hundreds of thousands of dollars for the finest and
most beautiful. Such high-end combo specimens may be
beyond your budget unless, of course, they are small.
Recently the shoebox at the end of my bench yielded
a handful of specimens purchased from dealers at the De-
Gold
continued from page 8
many other states. A large amount of gold is produced as
a by-product of the refining of copper and silver. The first
discovery of gold in the US was in North Carolina in 1799. For many years, mines in the Great Falls area of Maryland
and Virginia were large producers, and significant gold can
still be panned in the streams in that area. (Some of you
may remember Jack Nelson, who panned enough gold
from the streams in the DC area to make an engagement
ring for his fiancé.) Discovery of gold in Georgia in 1828
(followed by the first large “gold rush” in this country) led
to the establishment of a US Mint in the town of Dahlonega. The gold rush to California beginning in 1849 helped
to spur the westward expansion of the US, and the 1898
gold rush to Alaska and the Klondike had a lasting effect on
the growth and development of the Pacific Northwest. For
many years, the largest gold mine in the US was the nowclosed Homestake Mine in South Dakota, but very few gold
specimens came from that locality because the gold was so
finely disseminated in the host rock. The 1851 gold rush to
Australia helped to populate that distant continent. Other
countries with significant gold de¬posits are Canada, Mexico, Columbia, Romania, Russia, South Africa (the world’s
largest producer), Ghana (formerly named the Gold Coast),
India, and the Philippines. Historically, large amounts were
found in Bohemia, Turkey, Macedonia, Sudan, and Egypt,
but these deposits are now largely worked out.
Next in the series: silver.
The Conglomerate –February, 2015
text and photos by Mike Seeds
sautels Memorial Micromount Symposium in October 2014.
As I pulled them off their stuckum and mounted them with
proper labels, I noticed that a few of them were combos.
One of the most striking was goethite on quartz. Under
the scope the goethite showed up as delicate fuzz on the
faces of the crystal. The fuzz is brown or yellow depending
on the lighting, so as you tip the crystal the faces shimmer
and flash with color. But wait, there is something else going on. A black mineral has formed along the edges of the
quartz crystal, and as the crystal is nicely terminated, the
black edging outlines the faces like dark stitching. Is the
black stuff also goethite,
or could it be hematite?
I’ll vote for hematite, but
further research is called
for. Look closely and you
can see that the black stuff
has also formed a curlicue
across part of one face.
Perhaps there was a tiny
Goethite on Quartz
interruption in the perfect
Wallingford, CT
atomic lattice of the face
(field of view 6 mm;
and the black stuff atoms
46 frames, stacked).
found the edge, like the
edges of the main faces, especially attractive.
The little quartz crystal was so nice I could not resist,
and the dealer had a number of them, so I bought two.
They were $2 each! One goes into the collection and one
goes into my trade box.
Another nice combo was a specimen of bixbyite on
topaz from the Thomas Range, Juab County, Utah. Topaz
is just one of the beautiful minerals that come from the
Thomas Range, and this specimen has two topaz crystals
joined at the base where a black cube of bixbyite stands
guard. Perfect bixbyite cubes are always fascinating because they are so regular in shape they look artificial as if
they were cut on a precision milling machine. Of course,
we can credit the atomic properties of manganese iron
oxide [(Mn,Fe)2O3] for the cubic form. This specimen is
particularly attractive because of the contrast between the
polished black cube and the champagne colored topaz. In
fact, inclusions in the topaz crystals seem to emphasize
continued on page 10
Page 9
Shoebox Adventures
continued from page 9
the depth and transparency
of the crystals. The bixbyite
on topaz crystal was stuck
on ugly stickum in a little
cardboard box. It deserved
better, and at $3 it had to go
home in my shoebox.
Another specimen out
of the shoebox was a complicated combo of brookite
and quartz. Brookites from
Magnet Cove, Arkansas are
Bixbyite on Topaz
typically dark octahedrons,
Thomas Range, Utah
as in this piece, but the small
(Field of view 9 mm
42 frames, stacked)
brookite crystal at the top
seems to have some complex
faces. It and a small doubly terminated quartz crystal (slightly
over exposed in the photo) are located on a larger truncated
octahedron of brookite. The surface of the larger brookite
seems to be covered by a stepped pattern that is striking;
the buzzing atoms must have been obeying some interesting
rules when this crystal formed. To make the entire specimen
even more interesting, nature placed the large octahedron on
a shaft covered with small quartz crystals (at lower right in the
photo), so it looks like a brookite lollypop on a quartz stick. It
is really brookite with quartz on brookite on quartz.
This specimen came in a small plastic box with the stick
of the lollypop shoved into white foam. In fact, it was glued
into the foam with some
glue that was not water
soluble. It took a long
time under the scope
to pick off the bits for
foam and glue. At last
it was ready to mount
(with Elmer’s glue) in a
micro box. That’s a lot
Brookeite with Quartz on Brookite on
of fun and an interesting
Quartz
specimen for the bargain
Magnet Cove, Hot Springs Co. AR
(Field of view 10 mm
price of $5.
49 frames, stacked)
If you can afford
to pay as much for a specimen as some people pay for a
fine car, you can put some lovely things on your shelf. But if
you are on a budget, you can still find neat things for a few
dollars. Just think small.
Page 10
From the Federations
Eastern Federation News:
Ken Creed asks in “AFMS Scholarship News” What can
we do to help insure that we have someplace to collect?
One suggestion is to contribute to the AFMS Scholarship
Fund. The fund supports students destined to work in the
fields of geology and mining. Some of those students will
someday be in position to make decisions about access to
collecting sites by mineral clubs, and having had scholarship support from the AFMS Scholarship Fund may make
them more interested in welcoming collectors. In that way,
gifts to the fun are helping the future of mineral collecting.
Andy B. Celmer EFMLS Historian, continues his entertaining history of mineral collecting in his article, “Mineral
Collecting: 17th and 18th Century.” Some collectors were
quite active in the 17th century; John Stuart (1713-1792),
the Earl of Bute, is reported to have built a collection of
100,000 specimens. Collections of 10,000 to 40,000 specimens are reported. Not only did people collect minerals,
they began studying them carefully. Jean Rome de l’Isle
(1736-1790) and René Just Haüy (1743-1822) are the
founders of modern mathematical crystallography. Haüy’s
collection resides in the Natural History Museum in Paris.
More that 6,000 of his specimens still have their original
labels in Haüy’s handwriting.
You can read the full text of these articles and more by
downloading the EFMLS Newsletter at <www.amfed.org/
efmls/newsletters.htm>.
American Federation News:
Safety Chair Ellery Borow reminds everyone to check
“sell by” or “use by” dates on products in their home pantry, refrigerator, medicine cabinets and first aid kits as well
as club first aid kits. He also advises replacing items such
as adhesive bandages, hydrogen peroxide, that may be
stored in upopened bottles as these can be effected by
temperature changes and age even if they have no “use
by” date on them.
You can read the full text of these articles and more by
downloading the AFMS Newsletter at <www.amfed.org/
afms_news.htm>.
The Conglomerate –February, 2015
Gus’s Magic Face: Solution
continued from page 5
Upcoming Show Admission Coupons
Later that afternoon, the boys were at Bubba’s Beer
Bunker having a few glasses of coffee, when Eddie explained. “I didn’t figure it out. It was obvious. Gus rode in
and walked back in an hour and a half. (Eddie really said
‘One point five hours’. He talks that way.) So if you double that, two round trips riding and walking would take 3
hours. But that would be the same a one round trip walking plus one round trip riding. If you subtract off the round
trip riding, which would be only half an hour, that would be
3 hours minus 0.5 hours, and that’s 2.5 hours. So I didn’t
figure it out; it was obvious.”
Slick was drawing diagrams and doing arithmetic on a
napkin. After a few minutes he put his pencil down. “Yep,”
he said, “It’s obvious.”
Pudge spoke up. “I didn’t see the answer immediately like Eddie, but I did figure it out. A round trip riding and walking took Gus an hour and a half, but it only
takes 15 minutes to ride in. So Gus must have walked
for an hour and fifteen minutes to get back. If he walked
both ways, you would have to double that, and that’s
two and a half hours.”
The Conglomerate –February, 2015
Page 11
The Conglomerate
Mike Seeds, Editor
516 Bald Eagle Ct;
Lancaster, PA 17601
Upcoming Events
February:
25: BMS meeting at Natural History Society of Maryland. - 7:30 pm. See page 1 for program information. Meeting refreshments by Steve & Carolyn Weinberger.
March:
7-8: 52nd Annual Delaware Mineralogical Society
Show. Delaware Technical & Community College, 400
Churchmans Rd; Newark (Stanton), Delaware. Discount
coupon on page 11.
8: Daylight Savings time begins.
13: Chesapeake Gem & Mineral Society auction. Westchester
Community Center, Oella, MD - 7:30 pm. Directions at
<chesapeakegemandmineral.org> . 21-22: 51st Annual Montgomery County Show. Gaithersburg Fairgrounds, Gaithersburg, MD. Discount coupon
on page 11.
The Conglomerate –February, 2015
25: BMS meeting at NHSM - 7:30 pm.
27-29: EFMLS Convention & Show, Hickory, NC
April:
22: BMS meeting at NHSM 22: Earth Day
May:
24 - 30: EFMLS Workshop at
Wildacres. Bob Jones speaker. Info
and registration at <efmls-wildacres.org>
27: BMS meeting at NHSM
30: 26th Annual Chesapeake Gem & Mineral show at
Ruhl Armory, Towson, MD
Page 12