Black sands

Alluvial / Terrace / Deep Lead Prospecting

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ratters
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Black sands

Post by ratters » Thu Apr 24, 2014 10:36 am

Hi All,

Im interested in peoples opinions on this. One particular spot I have been doing a bit of sluicing the amount of black sands is off the charts, really chockers. After only a fairly short time running gravel through it you can see the riffles full of black sand and almost no blondes on top any more. Just concerned that maybe the gold isnt getting trapped because of this, if the black sand gets a bit compact in there and isnt fluid enough. Or am I worrying about nothing? I am catching gold regardless but Im not an expert on sluice efficiency and design and it is does appear to be something that matters, if all the different types of sluice designs are anything to go by.
Do any of you stop for regular clean ups or just run it till your finished?

Cheers,

ratters

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Philski
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Re: Black sands

Post by Philski » Thu Apr 24, 2014 12:57 pm

HI ratter. it would pay to keep them all. They may contain something valuable. Iridum and osmium are still pretty high priced and we have an occurrence of rhodium that's worth a stacks of money at spot alone. even if its just tin you could smelt your own pewter with it.

Ive hit a few places like yours. East and West Coast , Behind Scamander and fossey / que river area. The pan feels heavy before you start and get an inch or more of cons in the pan. The only way i can think of for cleaning the riffles is to increase the gap between riffles, increase flow rate or steepen the angle. Or sieve it all first will help.

I did see one flat board sluice that had rare earth magnets glued under it and the black sands built up and became the riffles. Another had a large magnet strip at the head and was cleaned off periodically. but, in all cases i would keep the black sands or some of it and have it looked at to see if its worth keeping. Some of the things the old miners threw out are valuable today.

Fox
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Re: Black sands

Post by Fox » Thu Apr 24, 2014 11:52 pm

Hi all, on the subject of the old miners throwing away stuff
of value, apparently down on the West Coast they would curse
the heavy grey metal that was so difficult to separate out from
the gold and would pick it out of the pan and chuck it into the
campfire. So if one could locate their old campsites.......?
I also once read somewhere that James McGinty, the finder of
Tassy's biggest nugget went on to prospect the Savage R and
some of it's tributaries. In doing so he found quite a lot of
osmiridium with the gold & feeling that it may one day be valuable,
saved it & put it in a jar. When this was full, he is said to have
buried it on a bend of the Savage.
Many years later when Ossy was commanding several times the
price of gold, he went back to dig up his jar only to find that things
had changed....and you can guess the rest.
Yep, somewhere out there is several kilos weight of Ossy just
waiting for someone to come along with a detector.

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Re: Black sands

Post by Philski » Sat Apr 26, 2014 3:02 am

Hey Fox and Ratters

That's an awesome bit of history Fox. Thanks. i think its really important if we can share some of the history of our pioneers and stick it on the internet, so its captured and recorded.

My mum lived on the Blue Tier at Lottah just west of the anchor road turnoff up the top. Crystal creek is a good spot with star sapphires and lots of gems and a small tin adit about 100m upstream is worth a look. its was a marked trail so pretty easy to find. Around the old bridge is easier access to get down, It looks steep up the top, but isnt too bad.

McGinty. i ment to write about him and will now, Ive been to 3 of his workings and he was a very important and successful prospector and built simply beautiful workings.

There is an image of him i will try and find tomorrow and see if i can use it. with his son and him with the two largest Osmiridium nuggets ever found , so he was obviously pretty good at it. 22oz from memory. There was talk he got the Gold nugget in from Victoria for the Rocky river one. But to find Osmiridium that size that could only have come from The Urals in Russia or here in Tasmania, And, the Russian stuff its more crystaline. He really did find it here so,, even though i grew up with our 7kg nugget being salted to get miners to the west coast, , it was probably spite from less successful prospectors, more than actual fact. His workings are amazing. They are the best i have seen for workmanship. you know its his ground by the way he stacked his rocks. Like the dry stone roman walls. Built to last eons. Rocky river, Whyte River and McGintiy's creek are all his work. His working are the only ones i have seen in Tasmania like it, they really need protecting in some fashion.
i did get a very good signal in McGinty's creek with a gpx5000, but i didn't have time to dig the target. be 3-5 grams. Pretty shallow, still there waiting for me,, i hope.. Ive not set foot in 19 miles yet. but will one day.

The below is his eulogy from The Examiner Dated 18th August 1920

TASMANIA'S LARGEST NUGGETS
The death of James McGinty, one of Tasmania's oldest prospectors, says the"Commonwealth Jeweller," recalls the fact that he was the discoverer of Tasmania's largest nugget. In 19I3 McGinty D. Neil, and T. Richards were working,on Rocky Creek, a few miles above its junction with the White River. They had not had very much luck, when one day they came on a pocket of small nuggets. They bid these under the floor of the tent, and said nothing about the discovery until McGinty unearthed one of 243z, when they brought their finds to Launceston. J. S. Kerr. a Launcestone jeweller, secured the right to exhibit the nuggets in the mechanics' Institute Hall. As the banks had made a practice of exhibiting free of charge any large flakes of gold they received from the mines
the public did not take kindly to paying is to see the nuggets, so the venture was a failure. There was talk of sending the nuggets to Hobart, so that A. J. Taylor, of the Tasmanian'Museum, took casts of them, but McGlnty and Co. would not wait F. and W. Stewart offered to take the casts II they could have the loan Of the nuggets for a couple of hours, but Kerr would not let the rival jeweller get hold of them. Finally, McGinty collected the nuggets and sailed for Melbourne to sell them to the Mint. F. and W. Stewart wired over to Willis and (o., who intercepted the nuggets before they reached the melting pot, made casts of the two largest, 243oz. i
and one 40 oz. and forwarded .them isok to Launceston by the;return boat. F. and W. Stewart forwarded copies straight to Hobart and exhibited them at their stand at the industrial exhibition which was running at the time. A few weeks afterwards, working at the same place Griffin, Watson, and iorgan discovered a nugget of 1440oz., and F. and W. Stewart made casts of this. Models Of these are
in most of the Australian museums.

taken from http://trove.nla.gov.au/ndp/del/article/51164762

ratters
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Re: Black sands

Post by ratters » Mon Apr 28, 2014 12:04 pm

Really nice info there Philski.

I wish I was collecting something valuable but in this case the black sands are all magnetic and from what I could find out neither Osmium nor Iridium are magnetic so I guess I'm out of luck there.

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Re: Black sands

Post by Philski » Wed Apr 30, 2014 9:11 pm

HI ratters. i know someone that is actually after iron ore like that. He is part Viking and wants to make a viking sword out of it. Using Tasmanian Iron ore and Forge it like they did many hundreds of years ago. Im part Viking too, so can appreciate why he wants to make it.

I also did metallurgy last year, so should be okay crushing, refining and smelting it to steel for him. Thats why he asked me about it.

have a great night
Phillip

ratters
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Re: Black sands

Post by ratters » Fri May 02, 2014 10:00 am

Wow thats an interesting project. Id be happy to save up some black sands and donate them to the cause.

Id also love to have a go at smelting metal myself, been meaning for ages to build a small furnace for that kind of thing, melted aluminium a couple of times but always fancied having a proper setup. There are plenty of guides on youtube and I especially like the waste oil burners, will have a go at building one eventually.

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Re: Black sands

Post by Philski » Wed May 07, 2014 2:49 am

hi Ratters

I did a bit of research tonight and the Vikings used bog iron and not magnatite or hematite. bog Ore is an oxyhydroxide that forms around springs and you can see it on the ground as that rusty deposit in stagnant waters. It looks a lot like Gossan. We get a fair bit of bog ore south of Queenstown around the Bird River. They thankfully also made iron from Ochre. Its a very crude process just a flu and chuck crushed and roasted ore in the top of large flue with crushed coked coal and some sea shells add wind and hey presto a matte. Simular to a blast furnace, Anyway, it had lots of impurities in the end product, but still useful and lethal. The folding was to remove the slag etc. The majority went into ship building.

They also made metal out of the similar iron deposits like we have in Tas. In other parts of the world. Iceland, Greenland, England, Canada etc. The vikings used what was available to them. plunder plunder plunder. Banded hematite, ochre, magnatite etc. The world was poor on quality iron ore till the Ural Mountain in Russia opened up in the 1600's.

The banded hematite you see was when algee and terestrial plants produced enough oxygen to acidify the worlds waterbodies and drop the iron to the bottom during the great iron dump. WA is still mining that event.

im going to do this as soon as i see him again. Ochre would be cool and way more abundant that bog ore...

They smelted Rust

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Re: Black sands

Post by Philski » Wed May 07, 2014 3:08 am

sorry i forgot, fun as hell but a bit dangerous. roast and mix the black sands you have with aluminium powder (ground foil will do) in a mortar and pestle, rollers, ball crusher etc, (mums blender) to v fine powder. Stick the mix in a terracotta pot or crucible or hole in the ground and ignite it with a Party sparkler and you will have almost instantaneous and workable iron matte and stacks of outstanding pyromania excitement with free explosive fire show in a matter of seconds in your own backyard! Its called a thermite mix. Do not do it inside.. and dont try and contain it

Hematite works

https://www.youtube.com/watch?v=M3ZkoNF2ybg

the vikings didnt have aluminium,, thankfully...

ratters
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Re: Black sands

Post by ratters » Wed May 07, 2014 12:25 pm

When I was younger, I was a hopelessly addicted pyro. You name it I made it, mostly skyrockets and aerial fireworks shells but I had a go at everything. Made a ball mill and turned out all sorts of things that flew and exploded. Made thermite a few times but never succeeded in anything that could 'melt through an engine block'. It's all gone now, eventually fear of 'the man' and all this terrorism hype got the better of me.
I still firmly believe that home made sky rockets and fireworks are as honest and innocent of a hobby as digging for gold but I wouldn't want to face the courts over it. Bloody nanny state.

Sorry that's a bit off topic, I have seen the rusty bog iron you speak of a few times actually.

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