Naked Science Forum

Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: paul.fr on 31/08/2007 09:32:39

Title: do i have gold, or fools gold?
Post by: paul.fr on 31/08/2007 09:32:39
i have taken Bass's answers and wrote them down so i don't forget, i am setting off to make my fortune. But how do i know if i have gold or fools gold in my pan?
Title: do i have gold, or fools gold?
Post by: another_someone on 31/08/2007 12:38:01
What is commonly known as "fool's gold" is I believe iron sulphide.

It will have a different density to gold, and will be more susceptible to attack by acids.
Title: do i have gold, or fools gold?
Post by: eric l on 31/08/2007 13:38:38
What is commonly known as "fool's gold" is I believe iron sulphide.

It will have a different density to gold, and will be more susceptible to attack by acids.

Difference in density : 

Crystal structure : 

Reaction with acids :  gold will not be dissolved by acids (except aqua regia) while pyrite will but not in a spectacular way !!!

If you are mining :  pyrite will give off sparks if struck with steel, while gold will not.

Although litterature states a melting point in the same range as that of gold, pyrite will be roasted if heated in the presence of air, giving off SO2.  But your cigarette lighter will not be enough for testing that.
Title: do i have gold, or fools gold?
Post by: Bass on 31/08/2007 16:36:39
The easiest test is hardness, gold is fairly soft, pyrite is hard (which is why the actors in old movies would always try to bite the gold nugget- if gold, their teeth would leave a mark, if pyrite their teeth would fragment- now you know why there were so many old toothless actors!).  Also pyrite will often have a coating of "rust" or iron oxide, or if you leave it in the pan with a bit of water will start to oxidize overnight.

Good luck on making your millions!
Title: do i have gold, or fools gold?
Post by: paul.fr on 31/08/2007 21:36:50
Thank you all. Bass, i will send you a nugget when i am rich.
Title: do i have gold, or fools gold?
Post by: Bass on 31/08/2007 23:11:05
I'll be counting the days [:)]
Title: do i have gold, or fools gold?
Post by: JimBob on 01/09/2007 00:27:41
Thank you all. Bass, i will send you a nugget when i am rich.

If you are asking about fools gold , your the right person to ask the question, ya know what I mean, nudge, nudge?

Title: do i have gold, or fools gold?
Post by: jysk on 15/09/2007 20:07:36
Stressing over identification takes a lot of the fun out of recreational panning. (Since examples of possible gold are so small, field tests are impractical.) Someone can stare at a flake of chalcopyrite with a 10x glass and for hours. Hours better spent shoveling and washing more material that might host real gold.

Just try to remember this;
There is no "I wonder if?", about gold. Any doubt for even an instant means that it's not.

It sounds like foolish advice, but you'll agree after a successful experience gold panning and wonder how you ever could have mistook something so unique as gold for biotite or sulfides.

Mike