How does one place a value on a nugget?

[4metals]

I was at a client last week and a 4 pound piece of gold "vein" came in encased in beautiful rose quartz. There was no way other than guessing how to figure out the quantity of gold in the piece. The XRF read 74% gold and 12% copper so the gold in the vein was truly gold.

Long story short, he crushed it up and melted it and recovered a nice button almost 5 ounces in size. The sad part was the natural beauty of the piece was gone. He asked me what I would have done and I said bought it outright and kept the natural piece. Then he said, OK without melting it how much would you pay? I said HMMMMMM.......

Any suggestions, rules of thumb, or do you just wing it?

 

[rbramsey]

Nuggets in natural form go for what the buyer is willing to pay, and what the seller is willing to accept. It will also depend on how aesthetically appealing the specimen is. Most will probably fall somewhere between spot and 3 times spot.

Richard

EDIT: corrected spelling

 

[jimdoc]

You didn't get a picture?

Jim

 

[4metals]

I should have, I don't think of my Blackberry as a camera so I didn't.

 

[mlgdave]

I would so specific gravity test on it to determine gold content and pay accordingly, its a simple matter of weighing in air and water and doing the math.

Bummer, I would liked to have seen it I BUY stuff like this all the time!

mlgdave

 

[dtectr]

Nuggets in natural form go for what the buyer is willing to pay, and what the seller is willing to accept. It will also depend on how atheistically appealing the specimen is. Most will probably fall somewhere between spot and 3 times spot.

Richard

I think you mean "Aesthetically" http://www.merriam-webster.com/dictionary/aesthetically?show=0&t=1297452889
rather than "atheistically" http://www.merriam-webster.com/dictionary/atheistically
but we got the gist of what you're saying :lol:

 

[FrugalEE]

I've recently gotten interested in nuggets and bought a few small ones. The ones I like the best have some visable rock in them. I realized that rock is less dense than gold, but until I just looked it up I didn't realize that there is such a difference. Gold has a specific gravity of 19.32 while normal rock is in the range of 2.2to 3.3. That includes quartz, limestone, granite, & marble. This should allow one to make a pretty good estimate on gold content.

mlgdave, I hope you can elaborate a bit on this topic. What, if anything might be heavy inside a stony nugget that isn't gold?

 

[rbramsey]

Oops...That's what I get for using big words, and then trying to cover it up with the spell checker.

Richard

 

[dtectr]

Oops...That's what I get for using big words, and then trying to cover it up with the spell checker.

Richard

Brother, Don't sweat it! I'm such a hillbilly I make BarrenRealms007 look like, well, 007! :lol: :lol:

 

[Barren Realms 007]

Oops...That's what I get for using big words, and then trying to cover it up with the spell checker.

Richard

Brother, Don't sweat it! I'm such a hillbilly I make BarrenRealms007 look like, well, 007! :lol: :lol:

Oh God you are totaly screwed then.. :mrgreen:

 

[HAuCl4]

I was at a client last week and a 4 pound piece of gold "vein" came in encased in beautiful rose quartz. There was no way other than guessing how to figure out the quantity of gold in the piece. The XRF read 74% gold and 12% copper so the gold in the vein was truly gold.

Long story short, he crushed it up and melted it and recovered a nice button almost 5 ounces in size. The sad part was the natural beauty of the piece was gone. He asked me what I would have done and I said bought it outright and kept the natural piece. Then he said, OK without melting it how much would you pay? I said HMMMMMM.......

Any suggestions, rules of thumb, or do you just wing it?

Weight the whole thing dry. Measure the volume of the whole thing by submerging it fully in a graduated vessel full of water, add water till the surface of liquid matches exactly the graduated line. The volume of the whole thing times the density of quartz minus...

you got it by now or will after reading this far. :lol:

Start the bidding as if it were 9999 and you can't go wrong!. 8)

 

[mlgdave]

heres my method, I did an 11 ounce specimen about 3 years ago and told the guy it had 5.86 OZT of AU in it, he crushed it, got it refined and it was 5.95 OZT so I was really close and he was really impressed

Figure out how much gold is in a quartz gold specimen. The simplest way to test specific gravity is this, weigh the quartz gold specimen in "air" and multiply the weight by 1.9, then weight the quartz gold specimen fully submerged in "distilled water" and multiply that weight by 3.1. Minus the wet figure from the dry figure and you will get a fairly accurate specific gravity for that specimen!! You can then approximate how much pure gold is in the piece by using the numbers above. This bases the gold at 85% pure and white or grey quartz with no pyrites or other host rock in it.

The way I do the test is to place my scale on the backs of 2 chairs so that I can put a piece of coat hanger across the weighing platten and hanging a string down from each end like a swing, and then tare out the scale to 0.00, I then attach the quartz gold specimen to the string to weigh it suspended in water, ideally the water should be distilled and chilled to 4 deg celsius but its not usually that critical to have water at its ultimate weight. (ie: closies count)

mlgdave

 

[HAuCl4]

quartz density 2.648 g/cc fact
metal density (assumption 74Au12Cu14Ag) .74x19.3+.12x8.94+.14x10.49 = 16.82 g/cc ***

rock weight 1,676 g measured
rock volume 300 cc measured
density of rock 5.586 g/cc computed

(5.586-2.648)/(16.82-2.648)=0.2073 ---->20.73% metal content---->15.55% gold content =259.8 g of gold = 8.35 OZ ish...

Reserve price at auction: .2073 x 1.676 x 32.15 Oz/Kg x spot gold in $/Oz

"This magnificent piece of natural gold, still in its beautiful natural quartz companion, directly from the mine, can be yours for the same price you would pay for a piece of jewellery containing the same amount of gold. You get to keep the silver and other minerals as a bonus, as they are natural companions to this unique sample of natural gold." *****

8) :lol: :shock: 8)






***from XRF or from average quality of gold in that mining area.

***** Notice the careful wording. Not a lie was told in the ad as written, yet it is purposedly deceitful as good marketing always is. :lol:

 

[4metals]

"This magnificent piece of natural gold, still in its beautiful natural quartz companion, directly from the mine, can be yours for the same price you would pay for a piece of jewellery containing the same amount of gold. You get to keep the silver and other minerals as a bonus, as they are natural companions to this unique sample of natural gold." *****

I thought you were a refiner....not a salesman!

 

[HAuCl4]

"This magnificent piece of natural gold, still in its beautiful natural quartz companion, directly from the mine, can be yours for the same price you would pay for a piece of jewellery containing the same amount of gold. You get to keep the silver and other minerals as a bonus, as they are natural companions to this unique sample of natural gold." *****

I thought you were a refiner....not a salesman!

Becoming a BS artist is a side effect of involvement in the metals business!. :lol: