Distinguishing the Different "Karat" in Gold

How to Distinguished the different "KARAT" in GOLD

For preparation you need the following:

Test Stone, a dark stone, used to test gold karat as well as silver and platinum. The object to be tested is scratched on the surface of the stone and a test acid solution determines the karat of the scratch.

Bottle of Nitrics Acid, also know as aqua fortis and spirit of nitre, acid for gold testing.

Cigarette Ashes and Water

Steel Sand Paper (Fine), alternative way to distinguised if the metal is pure gold or gold filled

Small Trangle Shaped File or "KIKIL", another alternative way to test the metal if its pure gold or gold filled

Here's the Procedure:

Rub the metal to be tested on the test stone and leave a very distinct GOLD DEPOSIT on it. Pour nitric acid on the half portion of the gold deposit and the other half as is and see any changes in color between the two for a few minutes.

If the color changes into REDDISH its 10 kt, LIGHT RED is 12 KT, YELLOWISH GOLD its 22kt. If the gold deposit is totally dissolved by the nitric acid, the metal does not contain any part of pure gold, therefore, it is NOT GOLD.

Here's the practical way of testing 18 karat up to 22 karat fineness in gold

Pour nitric acid on the gold deposit then pour cigarette aches once then pour again nitric acid and wash the test stone in water, see if there is any gold deposit left on it, see if the color is reddish brown its 18kt., yellowish golden its 22 kt., and if the gold deposit is completely dissolved, the karat fineness is lower than 18kt. 

Pure Gold - is gold inside and outside of the metal.

Gold Filled (G.F.) -  is the process of sweating gold all over the surface of a base metal or rolling a base metal on a thin sheet of gold with a different finenes in gold.

Gold Plated (G.P.) - is the process os washing a base metal with the different fineness in gold solution by means of ELECTRO PLATING MACHINE