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#1

AtomRat
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From: Katazone, VIC
Joined: 22 May 2014
Posts: 5,076
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19 December 2015 08:12 pm

Found this today and wondering if anyone can give me info about it. Its layered dark and light, a thick 1cm wide layer of 1mm pyrite cubes visible along with thin lines of micro pyrite. Some of the dark lines are straight, some wavy ( these smaller lines are around or under 1mm )

After a pan and crush of a 2" chunk. See the sulfides / pyrite crystals and dust to the left. Lots.
1450516059_14505098345560.jpg

The bits I got
1450516080_14505098456061.jpg
1450516105_14505098584612.jpg
1450516129_14505098660193.jpg
1450516152_14505098743974.jpg

Last edited by AtomRat (19 December 2015 08:17 pm)


Wisdom is knowing how little you know

#2

stalker
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Joined: 03 May 2014
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19 December 2015 08:17 pm

here ya go http://www.crystalvaults.com/crystal-en … dia/pyrite

or build a nice paved bbq area .

#3

AtomRat
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From: Katazone, VIC
Joined: 22 May 2014
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19 December 2015 09:02 pm

I know what pyrite and its uses are, but I'm more after geology answers explaing what creates this and its association with gold smile


Wisdom is knowing how little you know

#4

silver
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Joined: 19 December 2013
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19 December 2015 09:36 pm

Slate used to be clay,... that's what was used for damp course and roofing in the old days,.... that's if it is slate. big_smile


What a great day ! ,... " I'll see you in the field ".

#5

mfdes
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From: Hobart, TAS
Joined: 18 November 2013
Posts: 585
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19 December 2015 09:47 pm

I think it's fairly common for slates that were laid down as clays with high organic content to turn into shales with high pyrite content. Not sure why, perhaps the organic matter was high in sulfur?


SDC 2300. Tasmanian mad about sapphires and gold.
Check out my blog about prospecting in Tasmania: http://www.appleisleprospector.com/

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#6

Parks
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19 December 2015 09:50 pm

microorganism poo poo? smile

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#7

AtomRat
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From: Katazone, VIC
Joined: 22 May 2014
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19 December 2015 10:06 pm

Ill define it a bit more - this isn't very common unless your on the gold here. Parks, you should know what I'm talking about


Wisdom is knowing how little you know

#8

Parks
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19 December 2015 10:23 pm

AtomRat wrote:

Ill define it a bit more - this isn't very common unless your on the gold here. Parks, you should know what I'm talking about

After working construction in that heat today, Parks brain no work. I'm still trying to comprehend the question.

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#9

Parks
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19 December 2015 10:38 pm

I'll have a go.

Hold it like this
1450524862_1450516152_14505098743974.jpg

There's the layers from oldest to newest on top with the crystals of organic poo poo on top. A common formation in ancient river beds caused by the slow erosion of host rock and organic material

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#10

stalker
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19 December 2015 10:49 pm

the simple version = its old mud gone hard . that side of aust was under the sea a very long time ago . as the land rose it formed mud flats also dead sea life and vegetation sediments is part of the makeup . also that part of victoria was volcanic . so oil and coal and slates were formed during this upheaval .

4 users like this post: AtomRat, Smithy42, numpty, Havinago

#11

AtomRat
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From: Katazone, VIC
Joined: 22 May 2014
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19 December 2015 11:31 pm

Great answer stalker. Any clue as to why the pyrite is there? I do like the 'sulfer' content post above..that makes sense. Volcanic sulfur? Mixing with the dense red soils / clay here..hmm but these are now on top ( the red soils ...or its the other way around ) but I'm painting a picture now. The slate / shale also has oval whitish - grey blobs. Not sure what they are yet


Wisdom is knowing how little you know

#12

Parks
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19 December 2015 11:46 pm

Ohhh and Rivers with organic poo poo wasn't the answer. sad Funny I just call them rivers and don't look at it as sea.

#13

Parks
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19 December 2015 11:52 pm

Apparently there's slates near where I go prospecting that has fossils of plant life in it.

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#14

AtomRat
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From: Katazone, VIC
Joined: 22 May 2014
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20 December 2015 12:18 am

Alex? tongue

Last edited by AtomRat (20 December 2015 12:18 am)


Wisdom is knowing how little you know

#15

AtomRat
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From: Katazone, VIC
Joined: 22 May 2014
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20 December 2015 12:32 am

Woukd this slate be Ordovician or Silurian?


Wisdom is knowing how little you know

#16

Parks
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20 December 2015 12:45 am

The slate / shale also has oval whitish - grey blobs. Not sure what they are yet

Quartz. Its a crystal that grows in the gaps.

#17

Parks
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20 December 2015 02:43 am

AtomRat wrote:

Woukd this slate be Ordovician or Silurian?

The one I was talking about is Lower Ordovician. Apparently a really early form of a plant that was one of the first. Looks like an alpine moss and is a seawater plant or seaweed called a graptolite. At least everyone should understand now why we get nice flat slate pavers, and talking about pavers I just thought of some on the footpath of a mining town that are huge pavers and have pyrites the size of marbles sticking out. I'll take a picture next week.

Graptolites
1450540498_imagesty5xtgwk.jpg

Last edited by Parks (20 December 2015 03:13 am)

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#18

Parks
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20 December 2015 03:24 am

1450541753_1450516152_14505098743974.jpg

It's strange to think that the quartz and sometimes gold moved into the gaps with the use of steam and grew there with microorganisms. When gold is found in this rock it comes through in streaks, like lightning. I've heard of mining companies loosing all their staff because they heard of streakers on the field and bought into another mining company that was doing so well that they didn't have to work anymore.

#19

cecc
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20 December 2015 08:23 am

Wow so many smart people here who really know their stuff, totally impressed.


Bring On The Color

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#20

silver
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20 December 2015 08:36 am

Wouldn't the grey blobs have been like pipe clay in their day(maybe). smile


What a great day ! ,... " I'll see you in the field ".

#21

Dreamwalking
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From: Modbury North, SA
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20 December 2015 09:07 am

It looks to me to be most likely a banded fine-grained pyrite in shale and very likely formed in Precambrian times. Pyrite is common in many hydrothermal veins, shales, coals, various metamorphic rocks, and massive sulfide deposits. These sulphides originated as mentioned by Stalker whilst Australia was 80% submersed beneath the ocean, eventually in the drying stages the sulfate source becomes evaporitic gypsum which when subjected to metamorphism ( compression and heat ) created the pyrite crystals. The coloured bands are more so due sedimentary deposits of different particles sizes deposited during erosion ... same as when you are panning off ... the amount of force (water flow) determines the size and weight of your residue.


If you follow a track, path or road, your only going where someone has gone before.

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#22

Parks
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20 December 2015 10:14 am

Here's the link to how gold makes it's way into the rocks http://www.abc.net.au/science/k2/trek/4wd/Over44.htm for anyone who hasn't already read it.

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#23

Parks
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21 December 2015 12:30 am

silver wrote:

Wouldn't the grey blobs have been like pipe clay in their day(maybe). smile

It was all clay in its day. As it was deposited in thin layers upon layers of thin layers. You can see a small line just under the pyrites showing something happened at this time line and a change of clay happened. It couldn't have been a fire as the pyrites shows plants where only just evolving. The layers have a constant thickness, so may have a cycle, possibly yearly. After drying out to slate it was subjected to pressure causing the crack below the pyrite, the one below that which now contains quarts and the one below that on the bottom now containing quartz.

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#24

Parks
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22 December 2015 04:13 am

I started discussing this rock further but had a government prick start playing with my conversation, so sorry Atom can't reply anymore until we find out who and why a government employee or IT smartarse is hacking into the PA web site. sad

#25

silver
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Joined: 19 December 2013
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22 December 2015 05:44 am

We get that with television,.. just when the news is going to say something important the screen goes funny and you can't see or hear the good bit. hmm sad roll mad


What a great day ! ,... " I'll see you in the field ".



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