Step By Step Acid Test

Written By: Kevin Robbins, Gold Solutions

WARNING:  Gold testing is done with Nitric Acid.  It is very corrosive and should not be used around children and using gloves is suggested.


Step One:  Lay your gold jewelry out in an open manor so each item can be seen individually.  All like

items should be grouped together so only one test has to be performed for typical items like earrings.  All of your chains should be untangled and laid out in a clean manor with the jewelry so you do not get confused as to which ones have been tested.   If there are other precious metals you should separate them and test each one separately.

After you have separated and cleaned up all the gold jewelry you should apply a magnet to each piece to confirm it is gold.  Items that are not gold will not be attracted to the magnet.

Step Two:  Depending on your stone size, select up to five items to be tested and place them in line from left to right in a clear and orderly fashion.  Starting with the item all the way to the left, perform a 

rubbing on the stone for each item in the order unto which you laid out your jewelry items to be tested on the table.  When you are finished you items should be in the exact order your rubbings are on your testing stone.

This process will assure you that you do not confuse items and their gold content.  The rubbings should be clear and consistent in their spacing and approximately from one side of the stone to the other to allow multiple tests on each rubbing.  The rubbings should be darker and use a part of the gold jewelry that will not be seen in case you do not want to sell the gold jewelry.  This applies to all the precious metals.  When your five rubbings are complete, prepare to use the acid.

Step Three:  To establish efficiency, I like to start with the 14-karat acid.  It tends to be the most common gold and the hardest to read on the test results.

Place a small dab about 30% of the way in from the right of the first gold rubbing that corresponds to the item that it was rubbed with.  Do this consistently on each rubbing for all five locations. Careful to not allow acid dabs to run into each other.

Step Four:  When viewing the acid dabs, look for all the acid dabs that have disappeared completely.  If it has disappeared, take the 10-karat acid and dab a small amount of acid all the way the the right on

the end of the rubbing that has disappeared.

The reason it has disappeared is because of the acid concentration on the first test was for 14-karat acid.  This would mean that 57% of the metal is gold and acid dissolved it (For gold percentages based on the karat value please see my site education page at www.goldsolutionsoffortmyers.com/edu.html#.US5pV-sjpws.  There was less gold than 57% and therefore the metal completely dissolved.  The next test is 10 karat gold and if it again dissolves  the gold jewelry rubbing is not real.  If the gold jewelry rubbing does not dissolve we know it is 10-karat gold.


Make sure to replace the cap on each acid every time you test with that acid.  You should also keep some water available for errors or complications.  If you get some on your fingers your should put them in water.  Although it will not seem like it is burning them, your fingers will turn yellow very soon. Never touch your eyes when testing precious metals.

Step Five:  The acid that did not dissolve in step three now needs to be tested with the 18 karat acid.  With the same procedure you will dab a small amount of acid 60% of the way over from the right of

the rubbing.  Watch the acid closely and if the rub dissolves you know you have 14-karat gold jewelry since the acid you just tested with is made for testing 18-karat gold jewelry which has a 75% gold content in the metal.

If the acid does not dissolve the gold jewelry rubbing you know you have a gold content higher than 75% and needs further testing and move to step number six.

Step Six:  The next acid you will be testing with is 22-karat.  The same method applies when testing with the 22-karat acid.  This time dab a small amount of acid on the far left side of the rub you are testing.

If it dissolves, you have 18-karat Gold Jewelry, if it does not you have 24-karat.  There is no further testing required.  24-karat gold is 100% pure gold and nitric acid cannot dissolve gold in any way.

Special Noting:  14-karat gold seems to be the most difficult to read for some reason.  When you test the 14-karat, you may find yourself wondering if it has dissolved.  It will look like it has dissolved but not completely.  Unfortunately, this is how the 14-karat shows.  If you have any question test it with 18-karat and 10-karat and compare.  It will make you feel more confident in your assessment.  Silver and platinum are tested much the same way but the results must be discussed in further articles.


We have acid testing kits available for purchase and delivered to your residence for $49.95 (These include your platinum and silver testing also and it comes with a stone.

We also have kits for establishing a complete gold value on each item you may have.  Inclusive is an electronic scale and an acid precious metal test kit for $99.00 (Not for use with legal tendering).  If you are interested please respond to this post with a request.


Please send your questions to me at: info@goldsolutionsoffortmyers.com