Another great example of technology moving forward. This week, I rephotographed this specimen of malachite from the Jukes Proprietary Mine in western Tasmania. The specimen was collected by me 19 years ago, and photographed shortly after.
The difference is evident, but the original single shot photo is really not that bad!
The specimen was collected during a visit to the mine, one of a number of sites that I organised for the Mineralogical Society of Victoria members who were in Tasmania for the 2006 Gemboree.
Here is the trip report, written by me, and published in Mineralogica Tasmanica, the journal of the Mineralogical Society of Tasmania, in May 2006.
In the week leading up to the Gemboree, members of the Mineralogical Society of Victoria held a series of field trips in western Tasmania with me as their guide. Sites visited included the Princess Mine at Moina, Savage River, Bischoff, Kara, the Adelaide Mine, Mt Lyell and Mt Jukes. All in all, a very hectic but enjoyable week.
The week did not start off well, however, as Ed Richards had an incident which prevented him from joining us on the Sunday. His trailer decided to morph into a tree.
The numbers were made up though, with an international visitor β Chris Jewson from Cornwall, England. Chris is on a six-month Australian tour and Tasmania was one of the early stop-offs. Just had a card from him β heβs heading up to Broken Hill, the first part of a journey that will take him to many interesting places, including Whim Creek in Western Australia.
Also, as I write this β some late-breaking news. Some parts of Tasmania had their wettest and/or coldest April on record. The group was indeed very fortunate as the only rain that we had was on the Tuesday night and a few short showers later in the week. Very fortunate indeed. The worst forecast was for the day planned for Kara. Not a very nice place to be in the wet!
So, on to the site visits...
Princess Mine, Moina
Richard Wolfe met us at Moina and led us in to the parking spot by the lake. From here, we fought our way through to the mine. The Princess mine, Moina, originally known as Urquhart's Claim after the original lease holder, is located on the northeast slope of Dolcoath Hill, overlooking the Cethana dam, part of the hydroelectric scheme on the Forth River. It is one of a number of mines in the region that have been worked for tin, tungsten and/or bismuth. The largest of these is the Shepherd and Murphy mine. Other mines include the All Nations, Dolcoath, Sayers (well known for its beryl), and Pig and Whistle. The deposit was discovered by Warwick Castle in 1908, but mining activity ceased around 1918. Seven exploratory trenches were originally cut, but little of value was found. Warwick Castle himself controlled the mine for a while and extracted wolframite and bismuthinite, the only two minerals noted from there in the Catalogue of the Minerals of Tasmania. This mine worked two well defined veins up to 200 mm wide, containing bismuthinite and wolframite in a quartz matrix, with topaz and fluorite, in pegmatites near the top of a biotite granite host (Reid, 1919). Bismutite, tungstite and ferritungstite were also recorded in the oxidised zones. Bismuthinite reportedly occurred in long bladed crystals and delicate acicular forms. Numerous small wolframite-quartz veins occur in the quartzite overlying the granite. High quality smoky quartz crystals to 150 mm long, some enclosing bismuthinite and wolframite, occur in the lodes. The deposit has been developed in a shaft, open cut, adit and trenches, and proved the lode continuous over 100m vertically. There are three levels of workings still visible, with most activity centred around the top and bottom levels. The top level consists of a small adit that has to be pumped out before entering, where pockets of clay can, and have provided some stunning blue topaz crystals. The range of minerals found in the top level include quartz, wolframite, fluorite, bismuthinite, beryl and muscovite. The bottom level adit is proving to be interesting with a range of minerals having been identified, including bismuthinite, fluorite and monazite. I wandered up to the top workings on this occasion and found some promising signs of smoky quartz. pieces of large crystals, but unfortunately no intact specimens. As usual, finding our way back to the cars was a bit of a challenge. Those darn tracks are hard to follow!
Savage River Mine
Monday morning saw us boarding a bus at the Savage River Mine. This is my third visit to the mine in recent times and as usual, I was not disappointed. We headed up to a North Pit high-grade ore dump where there were some excellent pyrite specimens found, particularly by Volker Hoppe. These were sharp cubes, some loose, but some in serpentine, and very showy specimens. I found two extremes of magnetite specimens. One is a small (about 4mm) sharp octahedral crystal, the other is a large fibrous-looking magnetite crystal about the same length as a house brick. Unfortunately, our stay here was limited, as there was a blast scheduled and we had to be well clear. Our next stop was a waste dump from the Central Pit. This is the first opportunity that I have had to look at anything from the Central Pit, so I was interested to see what might be there. Some of the rock types are quite different with a fair amount of meta-basalt present. Mineralisation was sparse, but I did manage to find a nice hematite specimen. Our final stop was the abandoned South Pit. The water level has risen quite a bit since the last time that I was there, and the track in has deteriorated. It is still possible to find some interesting specimens, and I found some siderite and hematite to pass around. Wouldnβt you know it though. Just as I found a boulder with interesting-looking vughs, it was time to go!
Mt Bischoff
As we had finished reasonably early, I took a few people up to Bischoff. Chris spent all of his time looking for a decent cassiterite specimen (after all, he does come from tin country) and got a bit frustrated with his lack of finds. Others searched diligently for blue beryl and sellaite, and on the way back, malachite and brochantite. Iβve got some interesting-looking material from the beryl deposit (maybe one of the rare fluorides?).
Kara Mine
Sales of the Kara book were brisk the night before the trip π An early start on the Tuesday forced Chris to sit this one out. The weather threatened but held off. Kara produced some nice specimens as usual. Rhodochrosite, takanelite, calcite (including a new habit that I havenβt seen before from here), andradite and bavenite to mention but a few. I found a couple of hedenbergite crystals too which was a first for me. Volker has a specimen that he has not been able to identify. I hope to see a photo or two soon. That night it poured with rain. But we were all tucked up, trying to digest three nights of the Bischoff Hotel meals. They do some good food there.
Adelaide Mine
We all trundled off to Zeehan on the Wednesday. Our first stop was the Adelaide Mining Company shop where we were fortunate to see a couple of specimens that had come out of the recently opened pocket, named as the Premiere Pocket. I obtained a nice recent quartz specimen from Trial Harbour too. We headed off to the Adelaide Mine, Dundas where small groups went into the lower adit with Richard Wolfe. The excitement levels rose though, when one by one, we were given the opportunity to see the new pocket on the upper level. A wee bit claustrophobic but I wouldnβt have missed it.
Mt Lyell
The final day before heading back to Hobart saw us meet at the main gate of the Mt Lyell Mine at Queenstown. After a short induction, we headed up to the North Lyell area. There was not a lot found but there was certainly a lot of effort in trying. From here, we had a quick look at an interesting and important geological unconformity in a small quarry, not far from the Lyell Blocks area and then headed off the lease and down to the King Lyell area. Through a gate and across a creek and we were able to find bright native copper and brochantite-coated copper specimens. Our last stop was at Philosopherβs Ridge. I managed to find enough anatase specimens to pass around. Find of the day was a very nice quartz cluster. Finder was our guide!
Mt Jukes
As there were not enough people interested in the Underground Tour for it to be run, I took a small group instead to a small copper mine on Mt Jukes (Jukes Proprietary). Native copper, cuprite and malachite were found without too much problem.
Then it rained!
From the Bureau of Mineralogy...
Records tumble in a cold, wet and windy month - Tasmania in April 2006.
Record Highest Total Rainfall for April β Savage River Mine (311.7mm).
Highest Rainfall in 20 Years for April β Waratah (284.2mm), Zeehan (336.2mm).
Oof!
Below: Malachite, Jukes Proprietary Mine, Mt Jukes, near Queenstown, Tasmania Width of 6mm. A stack of 100 images. Click on the image for a higher resolution version.
Below: Same specimen photographed in 2006 using a Sony DSC-P150 point and click camera handheld to one eyepiece of my microscope. A single shot.