How can I tell if the gold i'm looking at, is real?

Answer 1

The magic word is "Assaying".

"Assaying of gold jewellery –Choice of technique" : http://www.gold.org/discover/sci_indu/GTech/2001_32/WOR82071.PDF

"Touchstone testing"

"Touchstone testing is an ancient method for measuring gold content whereby a rubbing of the jewellery is made on a special touchstone alongside rubbings of known reference samples and treated with acids. The colour of the reacted area is compared to that of the reference sample. It is not sufficiently accurate (about 15 parts per thousand at best) and is only useful as a sorting test to differentiate between different caratages. It is less accurate at high caratages and with white golds. A more detailed description of the technique can also be found in Gold Technology, No 3, January 1991."

"Other Methods"

"The Electronic Gold Tester (or the so-called Gold Pen) is a cheap, although portable technique based on the capacitance decay principle. Accuracy is poor, being correct to only 1-2 carats (4-8%) and is compromised if the surface is gold-plated, for example. It is useful only as a sorting test."

"The density of carat golds reduces as caratage is lowered and this gives rise to density measurement as a possible method of measuring gold content, using Archimedes principle. However, density is also influenced by the other alloying constituents and so the accuracy of the method is poor. Jewellery containing defects such as porosity would further reduce the accuracy of density measurement. It is not recommended."

"Assaying of Jewellery : Measuring the Gold Content (Fineness) of Jewellery." : http://www.gold.org/jewellery/technology/assay/index.html

"RS Mizar M18A9 Electronic Gold Tester" : http://www.ecrater.com/product.php?pid=882838

Answer 2

supposedly, biting it. Gold is soft, and you should be able to leave a dent with your teeth, unlike fool's gold or gold alloys, which won't give.

Answer 3

Send it to me and I will tell you,then I will send it back to you postage pre paid.