How Testing Gold Works

Posted on February 15, 2021

Testing gold at home can be a less expensive way of finding the value of the piece of jewelry or metal you have in your possession. Though a professional evaluation is the best route to take, some home gold testing kits can sufficiently tell you if what you have is real as well as the item's gold purity.

What Is a Gold Test Kit?

A gold test kit allows you to measure the value or authenticity of gold. There are quite a few types of kits available, but each is designed to do the same thing: tell you the purity of your gold. Whether you need to find out if a piece of gold jewelry is counterfeit or you need to know your gold's karats, using a gold test kit can be a useful method for finding the truth.

Each type of gold testing kit has its benefits and its flaws. Here are a few of the different types of test kits you might find, as well as other DIY methods you can use to test your gold:

Acid Tests

Acid tests are some of the most common home tests. They have been around for a long, long time, and they're some of the most accurate test kits you can buy.

How Does It Work?

To conduct the acid test, you will have to scratch the surface of the jewelry of the gold item. This will help the test deliver more accurate readings. You should have multiple acid strengths, each designed to test a specific karat level. You'll start with the lowest-grade acid ” likely designed to test 9-karat gold ” and then observe the reaction of the metal and acid. If the reaction area doesn't turn to a color on the provided color chart, you conduct the test again with the next level of acid.

What Are the Risks/Concerns of Using One? What Are the Benefits?

The obvious concern of using the acid test is that you have to damage your test item to conduct the test. Though gold is highly resistant to corrosion, any alloyed metals may not be, and your hands certainly aren't, so be sure to wear gloves when you conduct this test.

The benefit of the acid test is its affordability and accuracy. Acid testing gold is a method that has been around for over 1,000 years. Acid tests make it easy to find out if a piece of gold is real. This gold test will also give you a fairly accurate, although rough, estimation of the karat purity of real gold.

The Touchstone Method

Another tried-and-true way to test your gold is the touchstone method. This method also employs the use of acids to test gold, but it is fairly non-destructive.

How Does It Work?

The touchstone method is essentially a different type of acid test. You'll still need the acid kit, but you'll also require a flat piece of slate or lydite. Take your piece of gold and draw a line on the touchstone to leave a mark. You'll conduct the same acid test on this mark rather than the item itself. [1]

What Are the Risks/Concerns of Using One? What are the Benefits?

The touchstone method doesn't require digging into the gold item itself, but it does call for you to scrape your gold against the touchstone, which can also cause damage to jewelry or other sentimental items.

Electronic Testers

If you want a more accurate reading of your gold's purity, an electronic tester is a great option. Though they can run high in price, they are often more accurate than acid tests.

How Does It Work?

How this test works depends on the electronic tester you use. The most accurate ones by far use X-ray fluorescence spectrometers to analyze the item you test. X-rays are sent through the test piece to excite atoms, which emit radiation that the device reads. You'll get the exact karat of the gold piece.

What Are the Risks/Concerns of Using One? What Are the Benefits?

As we mentioned above, electronic testers can be very expensive. If you want to find the exact karat percentage of just one or two pieces of gold, you might consider simply having them analyzed by a professional.

However, if you think you'll find yourself testing a large quantity of gold, this route might be the best option. There is no more accurate method of testing gold at home than one of these X-ray testers.

Best Practices for Evaluating Gold

Here are a few things you should consider as you go through the gold-testing process:

  • Go with the professionals. The most thorough way of finding out the value of your gold or whether it is actually gold involves taking the piece to a professional. We suggest thoroughly studying reviews and business ratings before choosing a professional evaluator. If you plan on turning your piece of jewelry or gold into scrap gold, many services will conduct a fire assay test to determine the purity of the gold before they melt it down to be recycled. The fire assay method is considered to be the most accurate in determining gold purity. [2]
  • Handle acids safely. Acids may not corrode gold easily, but your skin is not as tough. Use professional-grade gloves to protect your hands from the acids you use to test your gold.
  • Be wary of destructive tests. Some gold testing methods will damage your piece of jewelry or gold. Try to test on spots that are easily hidden if you are worried about the item's aesthetics.

Whether you're testing a piece of jewelry to see if it's the real thing or you're seeing how much your scrap gold is worth, testing your gold lets you know how valuable your assets are. From the simply curious to the professional gold investor, knowing exactly what you have lets you know where you stand when it comes to gold.

Article sources:

1. Gemological Institute of America Inc. 'Bench Tip #9: Use the Touchstone Method for Testing Purity in Karat Gold,' https://www.gia.edu/bench-tip-use-the-touchstone-method-for-testing-purity-karat-gold. Accessed Sept. 10, 2020.

2. Pease & Curren. 'Why True Fire Assay Remains the Most Accurate Form of Gold Refining,' https://peaseandcurren.com/blog/2017/10/22/true-fire-assay-remains-accurate-form-gold-refining/#:~:text=Gold%20Fire%20Assay%20History,of%20gold%20alloy%20or%20ore.&text=Some%20refiners%20prefer%20this%20technique,to%20five%20parts%20per%20thousand. Accessed Sept. 10, 2020.