Wednesday, February 7th - Today I made a show report stop at Australian Outback Mining's tent in the Mineral and Fossil Marketplace between the Ramada and Executive Inn. Today's weather was windy with rather potent gusts and the excellent weather enjoyed by Tucson Show browsers since last weekend appears to be going south with another storm moving in. Owner/prospector/miner Glenn Archer and his lady friend Margy are shown above left holding down their tent. I appreciated the cool factor of their boxing 'Roo flag, no doubt displayed by Glenn and Margy with a good deal of Aussie pride.
My apartment is just a half a dozen or so blocks away and I had been stopping by Australian Outback Mining to visit with their tubs of slabs on pretty regular basis at the beginning or end of my daily rounds, as there is a convenient shuttle bus stop right next to their tent. One tub in particular contained pretty slices of a handsomely veined light green material that I thought was varisite. I had been pondering two spiderwebbed slabs in particular, priced at just $12 and $15, that were really eye catching and could have competed heads up on an aesthetic basis to my eye with some of the nicer spiderweb turquoise to come out of the American Southwest.
Those two slabs had been jumping out of the tubs at me as real gongas but I had so far somehow managed to resist them by reminding myself of several boxes full of must-have slabs for cabbing I have accumulated during past Shows and elsewhere, and that unless I were to go into the cab or jewelry business I probably already have enough material to keep me busy cabbing for the rest of my life. I'm sure many rockhounds are familiar with that drill... However, I've come to appreciate that when rocks keep calling me back like those two slabs they are usually something special and I had finally decided to add one of those spiderwebbed beauties to my cabbing rough collection. But when I returned to Australian Outback Mining today, someone with a bigger rough box than me also saw what I had seen and nailed both of those spiderwebbed slabs for their own.
As soon as I realized they were gone I felt pretty slow witted, as I certainly had plenty of time to think about them and it's not like they were unaffordable. So I did then what I should have done from the get-go, which was to ask if they by any chance had any more slabs like those two. Glenn knew immediately which two slabs I was referring to and unfortunately the answer was no. I also learned then that the material I had been admiring was not varisite, but massive magnesite, which is a carbonate mineral and ore of magnesium [MgCO3] that is in series with gaspeite [Ni,Mg,Fe+2)CO3] and siderite [Fe+2CO3].
Glenn related that this material came from near Kalgoorlie, Western Australia where there is a nickel rich belt several hundred miles in extent. Kalgoorlie is also central to Western Australia's gold mining region and is known as Australia's gold capital, being popularly referred to as the 'Golden Mile'. There are about 50 operating mines in this extensive region including approximately 25 gold mines and 8 nickel mines, most of which are around Kalgoorlie and in the northern goldfields. Other mines in this region produce copper, silver, granite, chrysoprase, gypsum, lime, salt and sands.
Despairing over my slow wittedness at that point, I asked Glenn if he thought there might be some more of the spiderwebbed material in a 55 gallon drum of uncut magnesite rough he had at his tent, whereupon he informed me that his spiderweb slab customer had also made a pass on the drum looking for more of the same and had purchased all that he found.
When I learned that this uncut rock was going for $3 per pound I decided to invest 20 or 30 minutes and make a pass on the rocks in that drum myself, hoping to dig out at least a small overlooked piece of the spiderweb large enough to yield a nice stone for a bola. While I didn't turn up any remaining material that I considered the equal of the those two spiderweb slabs that got away, shown above right are the three chunks weighing about 6 pounds total that went home with me. A 10x hand loupe provides scale. The 1 pound 6 ouncer shown in the foreground and up closer in the image at left was the nearest I found to those spiderweb slabs and it will be interesting to see what comes out when this one gets sliced up.
I also selected two other chunks of the magnesite that I thought had some good bola potential. One had larger dark veining and markings and the other featured more of a breccia effect with green pieces lithified in a reddish brown colored matrix, which may well turn out to be the most unusual and interesting of the lot with a little luck on the saw. Rough like this is a lot like a box of chocolates in that you never know exactly what you're going to get...;). However, I'll be surprised if these magnesite rocks don't yield some handsome bolas along with some good slabs for trading.
Glenn and Margy also displayed a good deal of gaspeite rough, both in a tub of slabs and as uncut rocks. As previously mentioned, gaspeite is a carbonate that forms a solid solution series with magnesite, with gaspeite being the nickel bearing end member and magnesite being the magnesium bearing end member. This material came from the vicinity of Widgemooltha, which is also located in that nickel belt in Western Australia and to the south of Kalgoorlie.
Gaspeite seems to be in vogue as a lapidary material, due no doubt to its being relatively new to US markets and its electric green color which is attributed to the nickel content. Glenn related that this material had been introduced at Quartzsite about 6 years ago and the more intense the green, the more it fell on the gaspeite side of the magnesite-gaspeite solution series. Glen said the material closest to the magnesite end of the series was typically white in color, so the magnesite he was showing contained some nickel and was somewhere intermediate in the series, with the visual distinction between magnesite and gaspeite being somewhat arbitrary. Gaspeite's formula [Ni,Mg,Fe2+)CO3] also indicates the presence of iron ions in its molecular structure.
The gaspeite slabs and rough shown above was also considerably more costly than the magnesite, due to its limited availabilty relative to demand. Really top pieces of hard, ready to cut material such as those shown on the 55 gallon drum top above left were fetching $125 per pound. Glenn was also selling lesser material that exhibited intense color but was softer and in need of stabilizing for $30 per pound. A quarter provides scale in the tub of gaspeite slabs depicted above left, which were priced from about $12 to $50 each.
While gaspeite's namesake is given by my Photo-Atlas of Minerals CD to be a locality (the Gaspé Peninsula, Quebec Canada) I think this material could just as well been named "Gasp"-eite after the reaction that would no doubt accompany encountering an outcrop or vein of it. I'm afraid the intensely saturated, nearly day-glo color of this stuff is just too much for me generally, but Glenn seemed to think it might grow on me and I was persuaded to take a small piece of it home anyway. In thinking of how I might employ some gaspeite in a bola or other jewelry I came upon the idea of a piece that would employ lapidaried bands of magnesite-gaspeite that graded across the solution series from magnesite white to gaspeite green as the nickel content became dominant over the magnesium. The more I think about that idea the better I like it and I might just pursue it in stone, but first I'm going to have to discuss the concept with Glenn to see if he could provide some white magnesite and more intermediate examples to fill in across the solution series and color spectrum.
Another green Australian rock that was shown and sold at Australian Outback Mining is chrysoprase, which is a gem variety of chalcedony that has enjoyed enduring popularity with lapidaries and has been employed in jewelry and ornamentation since the dawn of recorded history. Glenn related that this Australian chrysoprase occurred in association with the magnesite. It was selling for $75 per pound as uncut rocks. I did some digging around in the chrysoprase tub shown above and acquired a smaller, quarter or so sized piece of particularly gemmy rock to fashion a ring or necklace stone and there should be enough left for a matching pair of earrings, perhaps to fulfill my lady friend Kathy's request for 'something green' from this year's Show...
Glenn also showed some pretty veined chrysoprase slabs with other more homogeneously colored slices in a tub. The piece shown in hand at left was attractive to my eye, about 4" overall and it only wanted $4 to take home. It was a little on the thin side and 'pockey' with some small voids in a couple of places that would have probably interfered with a perfect surface and polish on a larger stone, but would have gone home with me for a bola anyway if it had only been just a wee bit wider as I appreciated the colors and veining. In retrospect leaving this slab and another shown laying in the tub behind it was probably another screw up on my part, as they could also have been cut up to yield a number of perfect, unpocked stones for an interesting matched set for a chrysoprase bracelet or necklace. You can bet all your yard rocks I will be checking out the chrysoprase slab tub for more like this at Australian Outback Mining early on in the hunt during the 2002 Show next year...
It wasn't all rough at Australian Outback Mining. Several flats of these selenites from Victoria, Australia were on display, priced at $150 per flat. Glenn related that these were not his in the sense of having collected them, as he was showing them on behalf of a mineral specimen dealing mate who was showing over at the Executive Inn.
You couldn't appreciate how interesting these specimens were until a plate was picked up and tipped to reveal the clusters that formed beneath the surface where these evaporite related crystals were deposited. These selenites are on the delicate side and must be handled carefully and properly displayed to avoid damaging them.
Another material of interest to me that was shown by Glenn and Margy at Australian Outback Mining were polished slabs and blocks of sectioned specimens that had been cut from Proterozoic stomatolites that lived about 1.1 billion years ago. The slab shown in hand above left was about 6" overall and I thought this one was particularly attractive due to the red pebbles and other conglomerate lithified in the rock beneath the characterisitically wavy growths of laminar stromatolite fossils. Glenn displayed a table covered with these slabs and blocks that ran from $8 for the smallest to $50 for a 10 pounder.
I related to these Proterozoic stromatolite pieces as they were very similar in age to some fine outcrops of Stromatolite Fossils in the Hakatai Shale I serendipitously discovered while hiking in the Grand Canyon backcountry last year. Out of curiosity at what his looked like I asked Glenn if he had any uncut pieces to show and he did, a couple of which are pictured above right and to the left. Of course I couldn't collect in Grand Canyon and I inquired if Glenn was offering the uncut material for sale. He responded that while he'd sold some of the fossils as rough previously, he'd recently decided not to sell any more as he wanted try cutting some of his larger pieces for displays, and also that the market for the sectioned and polished material had been pretty encouraging so he'd concluded he was just wheel spinning by continuing to make it available as rough to second parties.
I'm pretty content with collecting Grand Canyon stromatolites on film, but if I ever decide I need a physical specimen of a stromatolite fossil, Glenn looks like a pretty good guy to know. Proterozoic stromatolites got pretty good sized and I think a larger specimen that preserved the external fossil shape on one side and had a polished cross section to show the mounded, laminar structure of the stromatolites on the other side would be pretty cool. Hey Glenn, how about a pair of stromatolite bookends...?
Glenn also had a table covered with polished sections and blocks of 'Tiger Iron' from the Ord Ranges near Port Hedland in Western Australia. These had been pretty well picked over and significantly diminished in quantity and selection since the beginning of the Show but I still noted some pretty nice pieces remaining which ranged in price from about $5 to $35. The yellow bands of tiger eye running through it are chatoyant and really give this material some visual kick when it is rocked to and fro. The $35 piece of tiger iron in hand above left was my pick of the remainders. Tiger iron has become ubiqutous at Tucson and pretty nice slabs and blocks can be had relatively inexpensively. I have seen stunning cabs cut from this material and also some interesting carvings, but the bands of hematite running through it make it a very messy material to lapidary and polish.
Another Australian lapidary material offered by Australian Outback Mining is 'Peanut Wood', depicted above right, which are actually trace fossils left by ancestors of an extant genus of mussels. This material originated as driftwood which was attacked 'ship worms', which are Teredo sp. mussels characterized with a worm-like body, only a minimal part of which is covered by a shell. The wood protects the worm from predatory attack and its shell is used to bore circular tunnels. The ship worm lies securely in its tunnel and bores by pressing its body firmly against the tunnel walls while the notched shell is effectively rasped against the wood. The worm holes were filled in with the white material creating the peanut like shapes after the driftwood was buried in petrifying sediments. This material is from the Kennedy Ranges inland from Carnarvon, Western Australia. I noted polished slabs and blocks of peanut wood displayed on a table that were priced from $4 to $150. Glenn also supplies rough peanut wood rock for $3 per pound, a piece of which that's been roughly ground on to reveal the internal markings is shown in hand above right.
Glenn was also showing about 20 pieces of "Marramamba", a sought after red tiger eye from an iron ore mining district in the Hamersley Range in northern Western Australia. He related that maybe 20 tons of this material came out during the 1960s and then very little more except for a few tons he mined during the 1990s. Glenn said the pieces he was showing were the dregs from about 150 pieces of an old collection he had brought to Quartzsite this year and that virtually all the Marramamba had sold there before he moved on to Tucson. The pieces Glenn had left were pretty spectacular and I can only wonder what the creme de la creme he sold at Quartzsite previously must have been like. I failed to record the price on the particular piece I'm showing in hand but I seem to recall it wanting about $70 or so. Glenn said he is still prospecting for more of this material and that he dug for about 10 days not long ago but unfortunately no luck.
While visiting Australian Outback Mining I noticed a number of the other dealers in the area coming over to borrow their hand held, high pressure water sprayer and Glenn told me it was so popular he wished he had a dealership for them. These gizmotrons looked pretty slick to me for cleaning rocks and really getting off the crud and down into all the little nooks and crannies. From what I understand these sprayers go for a couple of hundred bucks, so I could see how Glenn had gotten to be a popular guy by making the use of Australian Outback Mining's sprayer freely available to other dealers showing at the Mineral and Fossil Marketplace.
Australian Outback Mining Mineral and Fossil Marketplace Email: firstname.lastname@example.org PO Box 517 Mundaring, Western Australia 6073 Phone: 011.610.41992.7750