525 jewelry made of gold

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Jewelry regulations require that the gold jewelry you buy or sell have a numbering. This last one allows to attest the presence of gold among the total composition of your jewelry. But some numbers are confusing like the 525 jewelry.

What is 525 jewelry? Is it real gold? How to check the gold composition of your 525 jewelry? We answer all these questions in this article!

The 525 stamp for jewelry

What does 525 jewelry mean?

The numbers you may find on your jewelry are related to the percentage of gold in the necklace, bracelet or ring. Numbers that contain 2 digits represent the gold karatage while numbers that contain 3 digits represent the number of gold parts in 1000. They therefore indicate the same information in two different ways.

525 means that your jewelry contains 525 parts of gold out of 1000. In terms of carats, this corresponds to 12.6k. (The "k" can also be replaced by "ct" on some jewelry.) Thus, two italy gold necklaces with the respective markings 525 and 12.6K contain the same proportion of gold to their weight. However, note that if one is heavier, it will contain more gold.

Also note that 12.6K contains a decimal and is not a round number. Indeed, 525 is not a common number in the jewelry world. 585 jewelry being much more common, your jewelry could actually be worth 14k gold. We have detailed the classic numbering in the jewelry industry to help you better understand the karesting system used.

What are the numbers used for jewelry made of gold?

  • 9 k or 375 : the jewel is composed of 37.5% gold. This numbering is mainly used in British Commonwealth countries or in France. However, it is not recognized in USA.
  • 10k or 416: this is the minimum USA standard you can find in the jewelry market. It means that the jewelry contains 41.6% gold.
  • 12k or 500: this is jewelry made of half gold (50% gold). You will not find this indication frequently. Indeed, they are mainly present on antique watches of collection.
  • 14k or 585: Gold is the main component of this jewel with 58.5% presence. Although common in USA, this number does not exist in Russia. It is replaced by the 584. The 585 jewelry is often produced in Asia and exported to foreign countries.
  • 15k or 625: Jewelry made of 62.5% gold is no longer produced since 1935 in the British Commonwealth where they were distributed. This numbering is therefore a good indicator that it is old jewelry. Attention, old jewelry does not necessarily mean that it has value. Everything depends on its state of preservation!
  • 18k or 750: The jewelry of 18 karat is composed of 75% gold. It is the first jewelry made in the high jewelry. Several exceptional 750 jewelry are sold each year.
  • 22k or 916: 22k jewelry is very expensive due to the 91.6% gold that makes it up. They are found mainly in Asia and the Middle East, close to where the gold is mined. Their yellow color is strongly influenced by their composition.
  • 24k or 999: This is jewelry made entirely of gold. Note that, despite what some unscrupulous jewelers may say, 100% pure gold does not exist. The term pure gold is relatively vague since it is given to bars whose gold purity is at least 99.5%. It should be noted that 99.99% pure gold was first produced in 1979 by the Royal Canadian Mint. Modern techniques now allow the production of gold with a purity level of 99.999% also called 5-9 gold, however, only the Royal Canadian Mint is able to produce gold of this purity at this time.

Is 525 real gold ?

If you bought your 525 jewelry in a jewelry store or chain store, you can assume that it is real gold. If you bought it second hand, you can also assume it is real gold, but it may be counterfeit. But do not trust nor the pretty vintage wooden jewelry box with glass doors used to display it neither the seller who provided it. Since the number 525 is not a classical numbering, it is impossible to determine it without having your jewelry appraised. To do this, several solutions are available to you.

Check gold composition of your 525 jewelry

Why check the gold composition?

If the international law obliges to mention the title of the gold of a jewel by means of a hallmark, it is often necessary to evaluate the title of the gold in a concrete way. It is often necessary to evaluate the gold grade in a concrete way, whether it is to resell a piece of jewelry for a private individual, or simply to repair or modify it for a jeweler. Indeed, the soldering of a gold object requires to use the right grade of metal to make the soldering. We use a filler metal with a lower gold content than the gold content of the jewel. Typically, to solder 18 karat gold jewelry, 16 or 14 karat gold is used. When reselling gold, both parties (buyer and seller) make sure of the quality of the gold exchanged in order to value the transaction. To do so, they can perform a chemical analysis with the Touchau test, an electronic measurement with a professional device or a wave analysis with a spectrometer.

Check gold composition with nitric acid

This is a must-have test for checking gold, which will suffice in 95% of cases. It requires a precious metal test kit. It contains different types of vials of nitric acid depending on the concentration with hydrochloric acid in order to test 18 carat, 14 carat, 9 carat and 22 carat gold. Given the difficulty in obtaining this acid and the safety risks inherent in performing this gold testing method, it is best that you leave it to a professional.

The first way to proceed is to rub the 525 gold jewel to be tested on a touchstone, also called a "touchstone", so that a few milligrams of gold are deposited. Put a drop of nitric acid on the gold trace left on the touchstone and observe the reaction to the nitric acid: if the mark deposited on the stone disappears, the test object is not made of gold; if the mark reddens, it is made of gold of a carat weaker than the acid used. If no reaction is visible, the gold test is conclusive and the 525 jewelry is gold corresponding to the acid used.

Another more advanced method of testing gold with acid is to file off an inconspicuous part of the object to remove the top layer, necessary with thick plating, and apply nitric acid to that area. A green reaction indicates that the jewelry is made of a metal other than gold or is gold-plated, and a reddish reaction indicates that the 525 jewelry is made of gold of a lower grade than the acid used. The main problem with this method is the need to take a sample of your 525 jewelry.

Check gold composition with spectrometer

A spectrometer is a measuring device used in spectrometry to break down an observed quantity into its simple elements which constitute its spectrum. For the gold test, we use an X-ray fluorescence spectrometer. When the test object is bombarded with X-rays, the material re-emits energy in the form of, among other things, X-rays and the X-ray spectrum is characteristic of the sample's composition. By analyzing this spectrum, one can deduce the elemental composition, i.e. the mass concentrations of elements and thus verify the concentration of gold contained in the tested object. This gold test is particularly effective in recognizing raw gold in the form of gold nuggets. This gold testing technique allows you to accurately analyze all gold alloys in a few seconds without damaging your 525 jewelry. However, the method we recommend is the third one because of the ease of access to the electronic measuring equipment.

Check gold composition with electronic measurement

The M24 is a professional grade gold tester that will test 9K to 24K gold. Mizar has other gold testers available that do not test the same range and Tri-Electronics makes several different gold testers. This tool is perfect for testing the gold composition of a 525 italy gold necklace or 525 jewelry in general.

Step #1: Remove the RS Mizar M24 gold tester from the box and make sure the 9-volt battery is in place. Put the tester on to see if it lights up.

Step #2: Use the gray eraser provided to clean the area on the piece of jewelry you plan to test. It is important to have a good connection and remove any oxidation. Attach the alligator clip to an area of the item you are testing, but not where you have cleaned. Be sure to attach to the surface of the gold, not in the area of the gems. This can be a little tricky on necklaces and rings that have gems.

Step #3: Press the button for the color of the gold you are testing - white or yellow gold. Use the white gold button for any item that is a silver color. The carat light will turn on. Ignore it.

Step #4: Add the test solution to the well on the gold tester. The test solution comes with the gold tester and more is available online. Squeeze the air out of the bottle before closing.

Step #5: Touch the cleaned area on the gold coin or platinum jewelry into the test solution in the well and hold it in place and watch for the "Test" light to turn on.

Step #6: Wait for the "Test" light to go off, and read the screen to determine the carat gold of the jewelry or item being tested. This electronic gold tester will tell you if the item is not gold or if it is platinum.


The 525 italy gold necklace or 525 jewelry in general represent jewelry composed of 52.5% gold, or 12.6 carats. This annotation is unusual and may be an error. Your jewelry could be a 585 jewelry whose "8" has changed to "2" over time. It would then be composed of 14 carats. To be sure, it is best to test gold composition with an M24 electronic measurement.

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