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!