The value of gold is based on the 'Karat' system, which is a 24 point scale that sygnifies the percentage of gold a piece of metal contains.

For example if gold jewellery is 14 out of 24 parts gold or 58.5 percent gold.and sometimes Halmarked '585'

The 'Acid test' is the cheapest method used to test gold. Simple acid test kits generally come with a black touchstone and several acid solutions, which are marked for different karats.

Experts start by scratching the touchstone using the gold that needs to be tested, leaving a streak on the stone.If the questionable gold is 14k, they will then make a paralell control streak using a piece of gold that is already known to be 14k. Finally they will put a drop of the acid solution on both streaks and compare the esuing chemical reactions.

Jewellers may also use electronic gold testers to figure out the quality of a piece of gold. Using a specific liquid or gel, they first create a circuit between the devices probe & the gold.The device then tests the golds electrical conductivity- this not only tells the jeweller if the material is actually gold, but also its purity. Electronic gold testers are fairly accurate when used properly (they must be fully cleaned of the gel in between uses)

The most accurate tests use Xray fluoresence spectrometers (XRF)  which is what we use at SA Gold Diggers Pty Ltd These machines are very expensive and send Xrays through the tested item to give an accurate reading of its content. (Zinc, copper, gold, silver etc)

Unlke the scratch test the XRF testing method leaves no marks on items and takes only seconds to give an accurate result.