Green Quartz ?

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headbut

Paul
Joined
May 13, 2013
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Location
Sydney, NSW
Hi Members

Need your help on identifying these rocks. They are quartz, with a green covering that seems softer and coarser than normal quartz. The smaller one is partly tumbled, as I noticed the green appeared to be wearing quicker than the quartz,I removed it from the tumbler.
This rock is heavy for its size & weighs 115 grams & if square , would be the size of a matchbox. The smaller stone is 47 grams
I have thrown a magent over it and nothing , so no iron etc.
1382947555_dsc_0091.jpg

1382948586_dsc_0093.jpg

1382948646_dsc_0099.jpg


Hoping it has gold in it :)

Thanks for any help

Edited for typos
 
Tricky one mate and hard to tell from the pic. Quite often Quartz is laminated with metamorphic Greenstone in certain shear zones. Could quite possibly be an example of this and the greenstone being softer would wear quicker, and not hold a polish being porous.

Sort of rock familiar to the goldfields so if it seems heavy for its size a SG test may put a smile on your dial. :)

Cheers Wal.
 
The polished one looks sort of metellic in the pic, interesting stuff. Copper, Silver? I honestly don't have a clue on that stuff.

Have a look on the DIGS site, type in the area you were in and it should come up with something about the local geology and rock samples metal content.
 
Looks very similar to what we dig out here, An old timer told me to keep a lookout for it in the creek, and as Wal said about sheer zones he said he had found a Dyke made almost entirely of it that had been "pushed up" and pulled a heap of gold out of it by cracking it out with a bar. I only picked my spot on the weekend cause I saw some protruding from the bank just above the water line and it worked a treat.
 
WalnLiz said:
Tricky one mate and hard to tell from the pic. Quite often Quartz is laminated with metamorphic Greenstone in certain shear zones. Could quite possibly be an example of this and the greenstone being softer would wear quicker, and not hold a polish being porous.

Sort of rock familiar to the goldfields so if it seems heavy for its size a SG test may put a smile on your dial. :)

Cheers Wal.

Hi Wal , picked it up at Tuena a couple of weeks ago from the dig hole & it is porous as you say , the triangle shape one feels normal in weight , so I thought of tumbling it , but the green would have been totally gone

Where would I get that SG test done or could I do it myself ?

Cheers Paul
 
Have found the formula , just need scales I can put in water

Now you have the dry weight and the wet weight of the specimen. Use the following calculation to calculate the amount of gold in your specimen.

- Subtract the wet weight from the dry weight and note the difference (D).
- Divide the dry weight by (D) and write down the result (SG) which is the specific gravity of the specimen.
- Subtract the specific gravity of quartz (2.60 to 2.65) from (SG) to get the result (R). The specific gravity of quartz varies from 2.60 to 2.65 because some quartz is more dense than others. This variation does not affect the result greatly, but it does show that the calculation, though close, will never be 100% accurate.
- Multiply the result (R) by (D) to get a result (R2).
- Divide (R2) by 25.97, which will give you the contained amount of gold in the specimen in ounces.
- Multiply the contained amount of gold in ounces by 31.103 to get the contained amount of gold in grams.
 
WOO HOO , if this test is correct , it has 17 grams of gold in it

Dry weight is 115 g , weight suspended in water is 77g & using above formula & picking 2.65 SG for quartz it comes back with 16.8 grams
 
Does this take into account the weight of the greenstone? Or is it calculated as if it is all quartz?
 
Confusing looking calculation you have there mate....lay mans version...

1. Weigh dry stone. "A"

2. Get small plastic container (eg marg tub), fill with enough water to submerge the stone without hitting sides or bottom. Tare your scales to zero.

3. Suspend stone and record weight. "B"

4. Divide "A" by "B"....that equals SG.

5. If SG is above 2.65 do a dance of excitement ;) .....but make sure no one is watching. :D

Cheers Wal.
 
WalnLiz said:
Confusing looking calculation you have there mate....lay mans version...

1. Weigh dry stone. "A"

2. Get small plastic container (eg marg tub), fill with enough water to submerge the stone without hitting sides or bottom. Tare your scales to zero.

3. Suspend stone and record weight. "B"

4. Divide "A" by "B"....that equals SG.

5. If SG is above 2.65 do a dance of excitement ;) .....but make sure no one is watching. :D

Cheers Wal.

I did mate , 3.02 :D
 
headbut said:
Balx said:
Does this take into account the weight of the greenstone? Or is it calculated as if it is all quartz?

True mate , then it would be more as that greenstone is lighter :D
Pic looks sweet, I have no idea about maths, so I am quizzing you. haha
 
WalnLiz said:
Confusing looking calculation you have there mate....lay mans version...

1. Weigh dry stone. "A"

2. Get small plastic container (eg marg tub), fill with enough water to submerge the stone without hitting sides or bottom. Tare your scales to zero.

3. Suspend stone and record weight. "B"

4. Divide "A" by "B"....that equals SG.

5. If SG is above 2.65 do a dance of excitement ;) .....but make sure no one is watching. :D

Cheers Wal.

Hi Wal , should it be divide A by C (diff between A & B) ?
 

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