Rock Identification

[Goldpick]

You are on the right track regarding the occurrences of base metals in the quartz, some of the quartz I found in north qld was very similar with occurrences of galena, chalcopyrite, pyrite, arsenopyrite, and of course gold.
I gather you have already read this:
http://www.resources.nsw.gov.au/__data/assets/pdf_file/0006/109554/stuart-town-gold.pdf

Quartz with galena and Gold from Qld:

 

[Village]

I think what we are incurring here is the problem between the deciphering of photos's and the real item. Many rocks on visual can look identical or similar. In the field three quick easy tests to confirm an identity is to streak test, cleavage test and hardness test. Usually the outcome of these three tests will allow you to identify a rock to a 95% probability in the field, without any real further testing.

Like in the case of Chalcopyrite, on visual it will look brassy when first broken, and tarnish over time, the actual streak test colour when drawn across a white plate will be metallic greenish black. Completely opposite to it's visual.

Streak testing is easy and cheap, you can find a set of plates here

http://www.pilbarageology.com.au/products/Streak-Plate-Set.html

Further confirmation is then confirm through hardness testing, through the use of a MOH's hardness set, found here.

http://www.pilbarageology.com.au/products/Deluxe-Mohs-Hardness-Pick-Set.html

Cleverage, well a hammer will help you here

If you have a real interest in geology, and want to determine the lithology within in an area, it would well serve to at least get a streak plate kit. Visual colours are highly miss leading, chemical weathering, trace element interaction and available lux of light can severely impede the identification of rocks based on colour, and or combination.

A lot of people carry a loupe as part of their kit, which is great, aids a on a percentage of rocks, or minerals by as siting the eye in identifying the crystal system of the specimen, but this really test no four in the sliding scale. Tests one to three should be completed first.

To complement all this a good field rock and mineral identification book is required, a good one, both in comprehensiveness and portability can be found here

http://www.abcmaps.com.au/Image Pages/rmpng.htm

Like I said doing it from photos is hard, and not being stubborn, until someone tests the original subject specimen, I'm not convinced based on the photos that it is chalcopyrite, but more then happy to be proven wrong, looks to grainy and loose in the photo.

Happy hunting

John

 

[Hare_Twigga]

Thank's GoldPick, Nice quartz you have there! Exactly the type I'm looking for. Interesting link too!

 

[Hare_Twigga]

Thanks John, I bought the streak test kit and the Mohs Hardness Pick Set. I worked out today that the pyrite/galena seems randomly scattered through out most if not all the quartz in this particular area. It will be interesting to learn to test these minerals for my self.

 

[Village]

Spectacular Hare!

You've taken the first steps out. The pocket field guide is the one I have used for god knows how many years, always good to refer to. When your ready and if you like, to take the next step, let me know, you will need a loupe , I have some sample kits which your are more then welcome to borrow, the Kits are by type actual rock samples and are numbered with a legend. This will take you into the third dimension of actual matrix and structure, looking at an actual sample of a rock. This does make it easier if you are at easy with the basic types, what they actually feel like, these range from group sets of

Sedimentary
Igneous
Metamorphic
Raw Ores
Fossils

You would need a loupe, a good white light, and for your own mind sake, a black light(although not a lot of difference)

Not for my samples, but you may wish to consider a small acid bottle, using a 10% dilution by volume for Hydrochloric acid, in the field the old acid test can sometimes tip the scale in your determination quickly. Bunning are good for the acid,

If your looking for good standard leather gear for your geo gear, you can't go past feller leather, they are the geo science leather makers, they make leather carriers for most geo gear, highly recommend it, everything from acid bottle carriers, hammer holsters and on and on. Use them all the time, they do post to Australia. Failing that if you want something custom at a reasonable price in leather, I use Ron at Outback Whips and leathers in regent st Broken Hill, I just send him the actual item with a sketch of what I want and how I want to attached it( 2" horizontal belt loops, or 1 in vertical belt) and he makes it, really great custom job.

The samples are yours to borrow when ever you want to try them, just PM me and I'll post them to you,

 

[Hare_Twigga]

Thanks Mate! Your guidance is much appreciated. I grabbed the book too... Knowledge is no weight to carry and I don't think you can ever carry too much. These are the veins I found that have the galena in them about 5ft wide I realized but they're sheared off, underneath is just clay... It's always fascinating finding thing's in the bush!

 

[heathcote]

mica schist is metamorphosed from clay the first is granite and the indentations could be from pyrite that has decomposed or somehow removed. cheers jan

Thanks Village! I thought it may be a granite but it's so fine grained that I wasn't sure if it was still called granite. I know where the rock came from but in the river there doesn't seem to be platinum,very rough gold and specimens to a point not far above a dyke of some description. Maybe the granite cooked to a mica schist if thats possible. I've loamed the area with no color though.

 

[Hare_Twigga]

Thanks Jan, I mentioned mica schist cooked from granite only because the dyke or slab of material in the creek is a mica schist I think... I'll take a pic of some!

 

[heathcote]

Hare_Twigga that photo with the mineral looking silver and shiney could be arsenopyrite and it is not a good idea to lick any mineral or rock. if it contains arsenopyrite it is arsenic hence the name and it is not always visible and quite often associated with gold etc. cheers jan.

 

[Hare_Twigga]

That's why I'm getting the thing's I need to identify them Don't wanna go poisoning myself :|

 

[heathcote]

The mineral with the striations in the crystals looks very much like a photo of bismuth that I found while looking for something else. Bismuth can be found with quartz which is what you have in the photo. Must be one heck of a backyard if you keep digging up these rocks! cheers jan.

 

[Hare_Twigga]

Haha! I wish they were all in my backyard! Only the pic I posted on the 24 January 2014 11:14 am was in my yard. This is the stuff I was calling schist.

150x

 

[heathcote]

Ummm not really sure. It certainly doesn't look like any schist I have though that is not to say it isn't schist. Have you tried scratching a bit of it... schist is soft and quite often "flakey". cheers jan.

 

[SuperPeter]

Hi all, any idea what this Is, I'm thinking quartz with pyrite. But I have no idea really any help would b great.

 

[SuperPeter]

 

[SuperPeter]

If these are not close enough I have a good zoom I can add more pics l8r if needed

 

[Hare_Twigga]

Looks interesting! Very hard to tell what it is though but definitely highly mineralized and worth further investigation. Crushing it to powder and panning it is a good start to see if there is free gold.

 

[SuperPeter]

I don't wont to crush yet, it will go in the fishtank b4 I crush it, I can get hold of a pinpointed that will show if there is gold, but I'm not holding my breath

 

[SuperPeter]

Would a jewellers loop pic of the silver stuff help, it is super soft stuff and squishes if pressed with ur finger nail, like lead but softer

 

[Hare_Twigga]

Yeah a close up pic would be interesting. Not sure if I'd put it in your fish tank,it may be toxic