|
|
Post by vcubitt on Jun 22, 2012 11:56:17 GMT 10
Hi all, I have recently discovered another mineral in my quartz vein - it is dark green and quite soft and it forms vein-like throughout a large quartz vein with hematite, limonite and goethite - but its veining is unlike the hematite. The other interesting thing about this mineral is when I heat it with a blow torch, it turns black and is attracted to a magnet, which is not the case prior to heating. I am wondering magnetite - but it looks very different to pictures I have seen and it bears no resemblance at all to the other iron oxides in the vein. I am waiting on result of analysis for the vein but that is not going to tell me what each visible consituent metal / rock is... Thanks in advance for any suggestions.
|
|
|
|
Post by jeffu on Jun 22, 2012 13:41:39 GMT 10
Hi vcubitt.
Don't know where you found it but it could belong to the serpentine group of minerals. Their constitution can vary quite a bit but one of the more common minerals of the group is ANTIGORITE (Mg,Fe)3Si2O5(OH)4. Olive green in colour and can be weekly magnetic.
ALL serpentine group minerals are asbestos based so be wary especially if it is slightly fibrous.
Jeff
|
|
|
|
Post by vcubitt on Jun 22, 2012 20:26:52 GMT 10
|
|
|
|
Post by vcubitt on Jun 22, 2012 20:29:38 GMT 10
Sorry - its about 10km from Majors Creek
|
|
|
|
Post by jeffu on Jun 22, 2012 21:25:27 GMT 10
Your location has pretty well ruled out serpentine. Without giving anything away, 10km from Majors Creek, which direction? I should be able to tell you what basic geology you are in. Majors Creek is right in the middle of several major geological structures. Andesite, Chert, Quartz feldspars, toscanite, rhyolite, porphry, granite and heaps more. A rough indication where it is will narrow the choices  |
|
|
|
Post by vcubitt on Jun 22, 2012 21:57:21 GMT 10
On the geological map, the quartz vein extends east from the boundary of the kain porphyry into the togganoggra rhyolite. Either side of the vein is the rhyolite. The rock immediately surrounding the vein and the minerals in the vein itself are dramatically distinct from the rhyolite which is very uniform in appearance. Thanks Jeffu |
|
|
|
Post by araluen on Jun 23, 2012 12:28:53 GMT 10
vcubitt
I know the are well. With hematite and quartz in that area my best bet is the mineral chlorite. It is often associated with alteration around hydrothermal veins. If it was a bright green then it could also be epidote which is very common in veins in the granite in that region but that is somewhat harder.
Araluen
|
|
|
|
Post by vcubitt on Jun 25, 2012 7:49:09 GMT 10
Thanks Araluen and all for suggestions, I think chlorite may be right - from what I have read chlorite is quite soft, the only thing that makes me doubt it is the streak, which is olive green with the mineral I have. I read the streak of chlorite is colourless. But everything else seems right.
I will keep on excavating the quartz vein and see what else I can come up with. The unweathered rock is very hard and the sledge hammer just bounces off the rock so any hints on breaking up hard unweathered bedrock would be great. I am down to a solid 20cm thick blood red vein running east-west through the quartz, it is bordered by some hematite that throws up a red cloud everytime I hit it with the crowbar - the red vein itself looks like photos on google of (maybe hematitic) jasperoid, but Im not sure.
I know that chalcopyrite is found in other veins within a km of the quartz vein, but I am not sure what it looks like in the oxidised zone. Does anyone know what it should like like among the weathered rock?
I'm hopeful that there may be a little Au in the rock somewhere and hopefully not locked up in sulfides...
Thanks.
|
|
|
|
Post by stack992 on Jun 25, 2012 16:40:21 GMT 10
Mate u really need to have this assayed so you can stop the guess work.I can definitely see some iron oxides,the rest I'm not sure about but what I do know is that you've got quartz in heavily mineralized ground.you could perhaps dolly it up so it's superfine and try panning it carefully,but I'd recommend you get it assayed properly by a lab
|
|
|
|
Post by vcubitt on Jun 25, 2012 19:25:33 GMT 10
Samples are with the lab now Stack992, but assays are only going to tell me what elements are present and the quantity - I am interested in knowing what is what if I can.
|
|
|
|
Post by vcubitt on Jul 30, 2012 20:54:03 GMT 10
Hi all, assay came back for the samples I sent in - three samples about a kilo each from three points along the 200 - 300m quartz vein which I have since discovered goes at least another 100m up the hill. The three samples were very different and represent about a 20m drop in elevation from east to west, with west being the lowest point on the outcrop. East and West were above the surface, central was about 30cm below the surface. West sample contained Gold (0.093ppm), Silver (2.2ppm), Copper (20ppm), Manganese (318ppm), Magnesium (1300ppm), Zinc (46ppm) and Iron (27400ppm) Central sample contained Iron (55100ppm), Silver (2.3ppm), Arsenic (53ppm), Lead (28ppm), Antimony (10ppm), Vanadium (34ppm) and Tungsten (20ppm) East sample contained Silver (2.2ppm) Aluminium (33300ppm), Barium (200ppm), Gallium (10ppm), Potassium (14800ppm), Lanthanum (10ppm), Sodium (400ppm), Phosphorus (50ppm), Titanium (400ppm) and Magnesium (1300). There were traces of Beryllium, Calcium, Cobalt, Chromium, Nickel, Scandium, Strontium, and Uranium across the samples. I really have no idea what these results mean for the prospectivity of me continuing to break up bedrock and try to go deeper. I can see that there is minute amounts of gold (but well above the background level of 4ppb for gold) and that it is at the lower part of the vein - could it increase with depth, and extend along the length of the vein? And is it likely that the silver content will increase with depth? If anyone thinks it a good idea I keep digging, how on earth do you break up bedrock granite, quartz and all this other stuff? I dont want to waste my time when I could be panning on the Shoalhaven nearby Many thanks... |
|
|
|
Post by someday on Jul 30, 2012 21:55:29 GMT 10
Hard call  going by your results, the east uphill trend is showing zip gold which is a shame because erosion would've been on your side! the west sample with minute trace's of gold could possibly be from surface drift contaminating the sample, who's to know?? also the west trend of your reef could be well an truly buried due to the easterly erosion and could continue on for ages. Ahhhhhhhhh  Try following the reef line to the lowest point and pan some deep samples! Alternatively go up the hill till you find the most erosion, then walk north and south and see if you can pick up other reefs and if there heading in the same direction?? Best of luck, it's good looking rock! |
|
|
|
Post by stack992 on Jul 31, 2012 16:41:05 GMT 10
The conversion of PPM if you dont already know is grams per tonne.You've certainly got some mineralisation going on.With the presence of arsenic and lead,that makes me believe that its a sulphide ore (lucky you).
Unless there is some gold value in the grams per tonne range I'd forget about turning a dollar from it.The only real way you can find out what you've got is by sampling the whole area and then you need the results analysed and perhaps get a geo-physist involved.This all costs $$$$$$.One thing I will say is that you've got all the indicators that suggest you could have discovered something quite significant whether or not it turns out to be commercial,probably not.9 out of 10 ore body's discovered remain in the ground because they are not economically viable.
You could be walking away from a fortune,perhaps not.
You need to spend some money and get a geologist involved to sample the area,they just know what to look for.They can tell you things about those insignificant rocks that will blow your mind.
Perhaps start with METSO's in WA,they might be able to point you in the right direction.
regardless of any the other metal found ,gold is the one you want.If you get sick of spending money on assays crush the rock up yourself so its as fine as dust and just pan it.You need to find free gold,but in most cases with sulphide ores its chemically locked up but it can be leached out.
Get in touch with Donnybrook as he knows the in's and out of small scale leaching with a product called CLS,relatively inexpensive,but remember if your not in the GRAMS PER TONNE RANGE with your gold content,forget it.And try spruiking the idea to small mining company's a great way to get your assays done for nothing is to send them quality ore samples along with some sort of proposal.QUALITY ORE SAMPLES,you a few steps away from this.Start with a field trip with a geologist let them choose the samples,perhaps even get a final year student to cut down on costs,you get the samples assayed and if you've got something significant put a Exploration lease over the ground,that process will take over 12 months but you can lock the ground up.
And start SPRUIKING!!!!! Enjoy the sleep that you've had because no doubt this will keep you up.
Good Luck,and remember to work smart.
|
|
|
|
Post by stack992 on Jul 31, 2012 16:44:51 GMT 10
|
|
|
|
Post by vcubitt on Jul 31, 2012 17:32:02 GMT 10
Thanks Someday and Stack992 - I guess your suggestions tell me the one thing I shouldnt do now ... nothing. If there is no commercial amount of gold there, it will still be a fun ride, so I'll keep going.
I have found one other quartz vein nearby (about 800m away and running southwest to northeast rather than east-west with similar mineralisation and a lot of what look like they call boxworks, but havent had it assayed yet. Will crush and pan it first to see what comes up.
The suggestion of a final year geo student is a great idea. I will see what I can dig up there, so to speak.
Have plenty of white, red, brown, green and purple running along the vein... I need some gold now...
|
|
going by your results, the east uphill trend is showing zip gold which is a shame because erosion would've been on your side! the west sample with minute trace's of gold could possibly be from surface drift contaminating the sample, who's to know??