Malachite
SOME GEOLOGY & GEMS
(A TRIP TO THE USA 2009)
In 2009 I was fortunate to spend some 8 weeks travelling through many of the national parks in the
western half of the USA. As part of that trip I visited a number of museums which had excellent
mineral/gemstone collections as well as 'rock shops' and national parks that demonstrate vividly many
aspects of the science of geology. The following photos are a very brief summary of some of the many
wonders to be seen in the western half of the USA.
L: Crater Lake N.P. in Oregon. Formed from the shattered
remains of an eruption some 7700 yrs ago, the lake is some
592m deep and 9.6km across at it's widest point.
R: The pinnacles, beside Crater Lake, are a colourful collection
of 30m tall spires that are being eroded from the canyon walls.
The spires are 'fossil fumeroles', each marking a spot where
volcanic gas rose up through hot ash deposits, cementing the
ash into solid rock
L: The 'John Day Fossil Beds', (Oregon) Painted Hills Unit. The
hills are the result of the erosion & weathering of volcanic ash
under a variety of climatic regimes. The area has yielded many
excellent fossils
R: The 'John Day Fossil Beds', Sheep rock unit has the visitor
information centre with fossil exhibits. This fossil skull has been
distorted by pressures underground, making it difficult to
identify.
L: A staff member at The 'John Day Fossil Beds' undertaking
work on fossils recovered locally.
R: A fossilised skull at the 'John Day Fossil Beds', Sheep rock
unit.
L: Butte, Montana, has been a major copper mining area, with a
large open cut pit replacing underground mining in 1955. The
mineral museum has a nice display of minerals and gemstones.
R: Butte museum, Butte, Montana. Sulphur specimen. The
museum is located on the Montana Tech Campus. It has over
1300 minerals on exhibit, including a 27.5 oz gold nugget.
L: Butte museum, Butte, Montana. Flourite specimen.
R: A geyser in Yellowstone N.P. The last major volcanic
eruptions occurred around 640,000 yrs ago. The central
caldera, some 75km across, is still underlaid by magma which
still powers the parks geysers, hot springs and mudpots.
L: Old Faithful Geyser, erupts at intervals which have varied
from 40 to 126 minutes. The time of the next eruptions can
generally be predicted to within about 10 minutes at present.
R: The Badlands N.P. in South Dakota show the effects of
sedimentation and erosion over some 75 million years. It is a
source of many fossils.
L: Mt Rushmore, South Dakota. This is a rather impressive
example of stone 'carving' compared to what most lapidaries
do! Constructed between 1927 & 1941, using dynamite and
jackhammers plus 400 workers; each face is 18.3m high. The
presidents (L to R) are George Washington, Thomas
Jefferson,Theodore Roosevelt , Abraham Lincoln
R: There are plenty of rock shops in the mining states such as
Montana, South Dakota, Colorado & Arizona. Lapidary shops
are less common.
L: Some of the petrified wood on display. Note the 'wood' from
arizona (red, white & yellow). I saw magnificent polished
sections of tree trunks (1m in diameter) of this material at
Bryce canyon in Utah
R: There are many nice agate specimens in the rock shops in
the USA plus fossils & minerals on display.
L: The shop had a wide range of rocks, fossils & minerals on
display.
R: You can purchase more than just 'rocks' at this shop.
L: A place well worth visiting is the 'Mammoth site' at Hot
Springs in South Dakota, just south of Mt Rushmore. A large
number of male mammoth fossils are preserved in situ in what
was a sinkhole. The site dates to approx. 25,000 years ago.
R: The many mammoths that died in what was a sinkhole, are
slowly being excavated by paid staff and volunteers. The site
dates to approx. 25,000 years ago.
The Denver Museum of Natural History
L: This specimen was dug up in the last few years by a fossicker.
It measures approx. 1m high!
The Denver Museum of Natural History is well worth a visit by
lapidaries and mineral collectors. It has a fantastic collection of
minerals & gems. To the immediate left are some crystals of
aquamarine and tourmaline.
L: This specimen is covered by gem quality beryl crystals, up to
10mm wide. The full specimen is shown above (the photo does
not do it justice). One of many high quality specimens at the
Denver Museum of Natural History, Denver, Colorado
R: A display of agates at the Denver museum of natural history.
L: Some of the lovely Rhodochrosite specimens at the museum.
R: A display of gold leaf specimens at Denver Museum,
Colarado. Part of a larger collection of gold specimens.
L: The 'rhodo pocket' from the famous 'Sweet Home Mine',
covered with gemmy rhodochrosite crystals. Approx. 3m long
by 2m wide.
R:A closer view of the 'rhodo' pocket from the Alma King mine.
L: The 'Alma King' specimen measures some 1m high and is
covered with fine quartz, calcite and flourite crystals as well as
the magnificent 'Alma King crystal'. Well worth a visit.
R: The famous 'Alma King' rhodochrosite specimen. The main
crystal is approx. 6" across.
The Colorado School of Mines Geology Museum,
in Golden, Colorado, has been in it's impressive new two storey
building since 2003. The current director, Bruce Geller & his
staff are very welcoming and informative. Well worth visiting!
R: A lovely specimen of Elbaite on Albite (200mm wide). One of
many high quality specimens at the Colorado School of Mines
Geology Museum
L: Flourite on Sphalerite, Colorado School of Mines Geology
Museum
R: Shorl on Albite v. Cleavelandite
L: A view of a small part of the interior of the Colorado School
of Mines Geology Museum.
R: Apophyllite with Stilbite from India, Colorado School of
Mines Geology Museum
L: The fossil displays at the museum are set up in a clear,
informative way. Grouping the fossils into their relative
geological eras provides a good sense of the progression of
fossils through those eras.
R: One of many displays of gems at the Colorado School of
Mines Geology Museum. The museum has very informative
labelling of it's displays.
L: Part of another display of high quality gems at the Colorado
School of Mines Geology Museum, the peridot in the centre is a
flawless 130.47ct gem.
R: A Rhodochrosite specimen to die for!
L: The 'Colorado Fire Necklace', featuring a magnificent
collection of faceted Rhodochrosites, is one of the attractions at
the Colorado School of Mines Geology Museum.
R: A lovely Aragonite specimen at the Colorado School of Mines
Geology Museum.
L: Monument Valley, Arizona.
R: Bryce Canyon, a classical example of differential erosion, is
one of the most beautiful national parks in the U.S.A. and a
'must see' for any visitors. Water erodes the rock both
mechanically (when fast moving water, carrying sediments,
abrade the rock) and chemically (as slow moving water enters
the rocks and dissolves the 'natural cements' holding the grains
of rock together).
A FANTASTIC EXPERIENCE -ATTENDING THE
2007 TUCSON GEM SHOW
I was fortunate to travel to the U.S.A. for the first time this year
and I made a point of visiting the Tucson Gem show. I am glad I
did the trip and would recommend it to other gem
collectors/hobbyists if they get the opportunity. The show is big,
really big! It consists of some 38 locations/'shows' around
Tucson, of which 13 were wholesale only.There are hundred
and hundreds of dealers covering all aspects of lapidary
work/mineral collecting/jewelry manufacturing etc. Many of the
shows are there to supply the professional jewelry trade but
there are also many applicable to the amateur lapidary
enthusiast/mineral or fossil collector.
A large range of equipment manufacturers were present
covering all areas of lapidary work (faceting equipment, laps,
saws, cabbing equipment, tumblers, sphere makers etc). I
found the the 'Tucson Electric Park Gem & Mineral Show' had
the greatest concentration of equipment suppliers this year.
Mineral specimens were available at many of the shows, but
the most spectacular/high quality specimens I saw were at the
'Tucson Westward Look Mineral Show' and at the 'Tucson Gem
and Mineral Show' (in the convention centre during the last 4
days of 'Tucson'). Faceting and cabbing rough was available at
several of the shows, including the JG & M show in Palo Verde (a
suburb of Tucson) and at the 'Globe-X/Days Inn' show in the
centre of town.
Photos: by row, L to R
1st row: The Globex show at Days Inn, Tucson, Arizona, U.S.A.,
2007. The show filled the motel plus a large number of
marquees. ; Some of the traders at the Globex show. There
were hundreds of traders at 'Globex', as there were at several
of the 38 sites around Tucson.
2nd row: Some of the cathedrals and caves at the Globex
show
3rd row: L Some of the cathedrals and caves at the Globex
show; R The 'Gem Mall' had a large range of beads,
manufactured jewelry and other items for sale
4th row: L to R
An impressive display of minerals including
Golden beryl crystals and rubellite/// The size and quality of
the crystals on display was most impressive, as this kunzite
crystal shows/// A magnificent azurite specimen.
5th row: L to R Goran (A geologist from Canada/Serbia),
holding a magnificent rubellite specimen at the Westward Look
Mineral Show/// A close-up view of the rubellite specimen.///
A large and rather magnificent aquamarine crystal valued in
excess of $80,000 (U.S.D.)
6th row: L to R An impressive malachite specimen./// A lovely
aquamarine specimen./// This large quartz crystal was
covered with a coating of multi coloured calcite, making a most
attractive specimen.
The Tucson Show Guide, which is provided free at the shows,
gives a detailed listing of where all the dealers/traders are
located, and should be studied carefully to ensure you make
good use of your time at the shows. Regular visitors to the
shows are also a great source of knowledge.
During the 2 weeks duration of the 'shows', a free shuttle bus
service enables visitors to travel around the various locations.
Based on my limited experience this year, I would say that you
do not really need a car when attending the Tucson shows.
There were plenty of Australians at the show this year, with
Australian gems/minerals being a special feature at this years
show. I attended several lectures by Australian
miners/cutters/dealers and was impressed by the way they
represented Australia. Well done!
One of the advantages of attending the show was meeting a lot
of friendly and knowledgeable fellow lapidary enthusiasts and
mineral collectors. A second positive was the quality of gems
and minerals on display. They were better than anything I have
seen in the past and I now appreciate what people mean when
they talk of really top quality gems and mineral specimens.
View the slide show to the left for more photos.
THE GIA AT CARLSBAD
As well as the Tucson show I visited the Gemmological Institute
of America's Campus at 5345 Armada Drive, Carslbad in
California (it is almost next door to 'Legoland'). If you are in
California it is well worth a visit, the GIA run tours of the facility
and you will see a great selection of crystals, cut gems and the
like. It is necessary to phone ahead to book in if you wish to
visit the campus.
Photos: L The entrance to the GIA campus at Carlsbad in
California.
R The musical instruments for an orchestra
produced from carved gem material and gold.
SMITHSONIAN MUSUEM,
WASHINGTON DC, USA, 2011 TRIP
During 2011, as part of a trip in the eastern half of the USA, I
was fortunate to visit the Smithsonian Museum of Natural
History, in Washington D.C. I had read that it had a fantastic
mineral & gem collection, and I was not disappointed. Well
worth a visit if you have the opportunity. Some of the collection
is shown below, though the photos do not do the collection
justice. However I am sure you will enjoy the mineral
specimens and gemstones shown, I went back to the museum
on 3 consecutive days to try to absorb the beauty of the
collection!
L to R: A magnificent Apophyllite and Prehnite
specimen; Some botroyoidal
Hematite; A specimen of Azurite with Malachite.
L: A typical display in the museum, well labelled and
lit.
R: A fine collection of metal/mineral specimens,
showing a variety of forms.
L: A collection of copper based minerals from the
well known location of Bisbee, Arizona, U.S.A.
R: A display highlighting the aesthetic appeal of
mineral specimens.
Magnificent ‘blue cap’ tourmaline specimens in
their display cases.
L: An attractive display including Rhodochrosite and
Varascite specimens.
R: Rhodochrosite!
L: A spectacular specimen of Rhodonite.
R: More Rhodochrosite
L: A display of Indian zeolites from the Poona
district.
R: Some impressive Elabaite (tourmaline) crystals.
L: The largest faceted Chrysoberyl gemstones I have
seen!
R: Three magnificent ‘blue cap’ tourmaline
specimens in their display case.
L: A 51 lb pink Topaz crystal, quite spectacular (gem
quality).
R: Emerald jewellery
Magnificent ‘blue cap’ tourmaline specimens
L: Beryl (aquamarine) on Albite
R: Two lovely Beryl gemstones.
L: A Beryl (Helidor) crystal, approx. 200mm high.
R: Faceted beryl gemstones.
L: Dioptase crystals on Calcite
R: Faceted topaz gem.
A magnificent emerald.
Photos below: Two of the very large and spectacular
fossils on display
The video below is a MPG4 video and should not be watched
unless you have internet download speeds of 3 or more
Mb/s and unlimited download allowances. It shows some
parts of the Smithsonian museum’s gems & minerals
displays.