Specific Gravity test help - Gold and quartz

[Campfish4x4]

Hi all I've gotta specie that weighs 25 .68 g dry and 2.99g underwater on a line so how much qaurtz is hedden in the nugget thanks and merry Xmas to all

 

[BigWave]

Hey CF4x$, I think your weights are incorrect.
Suggest you check and re-post.
Also, is the host rock pure quartz, or is there some ironstone present as well?

 

[Simon_49]

From what I have read in books, the specific gravity of gold is 19, that is, if you compared the weight of a cubic centimeter of pure gold with the weight of a cubic centimeter of water, the cubic centimeter of pure gold will weigh 19 times heavier than the cubic centimeter of water, hope that helps.

 

[Campfish4x4]

Weight is right it's mainly gold with a bit of qaurtz on one side unless you looked closely you wouldn't see the qaurtz

 

[condor22]

SG of pure gold is 19.32 - SG of quartz is 2.72 .

So from your description, the bulk of your weight is gold. The only way to ascertain the gold actual weight is to remove the quartz in acid.

 

[BigWave]

Mate, as I said, your measurements are wrong.
If your sample (dry weight 25.68g) was pure quartz, then its weight in water would be close on 15.99g (i.e.: displacing approximately 9.69g of water).
If your sample was was pure gold, then its weight in water would be around 24.35 (displacing 1.33g of water).
So you have your measurements screwed up.
No way its weight in water could be 2.99g if the dry weight was 25.68g
Try again

 

[Northeast]

There are also different methods in here.

https://www.prospectingaustralia.com/forum/viewtopic.php?id=25610

 

[Campfish4x4]

Thanks for the info everybody ive screwed up somewhere but the figures are right like I said its a solid nugget with tiny qaurtz inclusions in it BW could you explain how you do your specific gravity test and the formula you use cheers

 

[Pete's Pick]

You have aproximately 20gr of the yellow stuff!

That is awesome.

 

[Campfish4x4]

Thanks Pete merry Xmas and all the best for the new year

 

[Goldtalk Leonora]

SG tests on species are unreliable at best...being a bit blunt as I tend to be...they are a waste of time in terms of working out your Au content.

If the specie is 'pretty', and you wanted to sell it.....weigh it as is and charge a per gram price as is...gold and rock...that's your premium if it's pretty.

If it's a dog...and you want to work out the Au content....throw it in the dolly pot and smelt...only reliable method.

 

[Skip]

Hey 4x4 have you got a pic we can take a look at. Might help.

 

[Campfish4x4]

Thanks fellas for the life of me can't upload pic but if someone pm there pH number I'll send it to them to upload thanks I've got more as well

 

[wiley coyote]

Can anyone tell me what I'm doing wrong? I've got a nugget which weighs 359.6 grams dry, Wet weight is 351.4. I've used the tables available, but my end result is 5 grams heavier than the actual nugget. Mathematics were never my forte.

 

[BHM14]

A bit late at night to do the maths but I found this. I guess youve used the same formula.

The Specific Gravity Test is used to calculate the gold content of gold nuggets that contain a mixture of gold and other materials. In this example of the specific gravity test, we use gold mixed with quartz.

Nugget weighed in air weighs 96 grams

Nugget suspended in water weighs 74.5 grams

96 - 74.5 = 23.5
96 divided by 23.5 = 4.17 (the specific gravity of the specimen)
4.17 - 2.63 (the average specific gravity of quartz) = 1.54
1.54 x 23.5 = 36.19.
36.19 divided by the constant 25.97 = 1.39 ounces of contained gold
1.39 ounces x 31.103 = 43.23 Grams of contained gold.

The specific gravity for quartz is 2.60 - 2.65.

 

[AngerManagement]

??? A 10oz nugget WOW nice...

How are you doing the density test ?

Did you tare/zero the Cup and Distilled water

What is the accuracy of the scales as for small items you need at least 2 dec points. But at 350g that is not small...

Below is a simple method that works well for many items I often test... When Gold is in Quartz etc it can get a little more involved....

But this method and the chart helps for when doing unknown rings etc. Very handy and SUCH simple maths.

https://www.goldpay.us/specific-gravity-gold/

https://www.goldpay.us/wp-content/uploads/sites/2/2017/01/sg-07-density-table-300x203.jpg

 

[BHM14]

That example is wrong from the first line!

 

[HarryHoudini]

Hi Guys, General Hercules has a really good video on the subject and explains the process really well.
The General is one of our characters who has for many years provided some great videos and entertainment.
Love this guys outlook on life and honest persona.

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

Cheers

HH

 

[Goldtalk Leonora]

where your going wrong is using a SG test at all....whatever figure you come up with is unreliable.
The only way of knowing the gold content is to put it in the dolly pot.

 

[Guest]

where your going wrong is using a SG test at all....whatever figure you come up with is unreliable.
The only way of knowing the gold content is to put it in the dolly pot.

Gday

I agree totally, you might have a win if you are buying a specie, but chances are you are missing out if you are selling one, 8.( better the pot unless its a spectacular piece that is worth preserving.

cheers

stayyerAU