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999 Gold Guide - 24K Gold

If you are anything like me, then you are one of those who find gold completely irresistible. Whether it’s buying jewelry, collecting coins, or just window shopping, nothing leaves me drooling any more than seeing that beautiful, shiny, bright yellow.

When I began my golden addiction, one thing that often caught me off guard was a bunch of random numbers and symbols I would find stamped into golden jewelry. What are these random stamps, I would ask?

Stamps on gold jewelry are anything but random and say a lot about the jewelry. In this article, I will focus on the stamp that reads “999,” what it means, what other symbols you might find with it, and so on.

999 Gold Percentage

As evidenced by the title of this section, the 999 stamp refers to the purity of the gold, but it means virtually nothing when you have not a single other purity to compare it to. So what does it mean?

Common outside of the us is a gold purity system used called Millesimal Fineness, which is nothing but a measure of the gold content of the piece in parts per thousand. When converted over to parts per hundred, or a percentage, it tells you that the piece of gold you have is in fact 99.9% gold, or pure gold!

But, here in the US, we are bent on the Karat system, so what does this mean in karats?

  • Karats measure parts of gold, with the highest “parts” being 24K, so any Karat ring you have would have to be divided by 24K to get the percentage of purity.
  • Knowing the above, you should assume that 24K is the purest form of gold, or equal to 999 gold.
  • The math would go like this: 24K/24K=1, or .999 rounded.

Essentially, saying you have a ring that’s 24K gold is the same as saying your ring is pure gold, or 999 gold.

Uses for 999 Gold


Since 999 gold is pure, it’s extremely malleable and not the best for making jewelry, unless all you are concerned about is the value of the piece. If value is what you are looking for, your best bet is to buy gold coins which are often made of 24K or 999 gold!

Now, when you do find a piece of 24K jewelry, it’s immediately obvious by how bright of a yellow it is. It’s a kind of yellow only seen in pure gold! This means that you will not find a piece of 24K white gold or rose gold, as white gold and rose gold are made using an alloy, which means adding other metals to the gold to achieve the desired color.

Although pure gold is hypoallergenic, shiny, beautiful, and highly valuable, there’s drawbacks. I say it’s not the best for jewelry because of how soft pure gold is. If you must have 24K gold, I recommend a nice pair of earrings so they are not subjected to outside damage.

Gold Plating

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Very commonly found in 24K jewelry are gold plated or gold filled jewelry which is a way to get some 24K gold while getting the strength of other metals.

Always ask about the gold you are looking at if you are looking for pure gold, and double check those stamps to see if you find any markings indicating gold plate or gold filled: GE (Gold Electroplate), HGE (Heavy Gold Electroplate), or GF (Gold-Filled).


If you plan on buying gold as an investment, you'll be most interested in .999 gold. You can invest in coin currency that is minted in .999 gold, or opt for non-currency gold coins and bars, also referred to as gold bullion.

Gold bullion is measured by troy ounce, and is priced by the market, called spot price.


Did you know there's even gold in your cell phone? That's right. Gold is used in many of the handy tech gadgets you use everyday! Gold is a great conductor of electricity and does not tarnish, providing electrical currents a reliable path between contact points.

Now don't get too excited, there's only about $.50 worth of gold in the phone of yours.

999 Gold Hallmarks

If you come across a piece of 999 gold, or any gold for that matter, you’re likely to find stamps on the inside of it consisting of letters, numbers, symbols, or a combination of the three. These are called hallmarks and tell you all sorts of things about the gold such as the purity, who made it, where it was made, when it was made, and so on. It’s rather important stuff! Hallmarks laws differ from country to country, so not all gold will have all types of stamps.

In the US, there really isn’t a strict hallmarking system outside of the Karat stamp, and often a requirement to have a manufacturer stamp accompany that purity stamp. Outside of the US, however, there’s different systems in place, such as the one over in Europe where the Millesimal Fineness system is used.

A piece of jewelry is made, stamped with the maker’s mark and sent off to an Assay Office who will test the jewelry to verify the stated purity, then they will stamp the jewelry with their personal mark, basically certifying that the ring is indeed gold. Assay office marks will vary from office to office and change over time, making it a dating tool as well.

Regarding the purity stamp, you’re likely to see a shape surrounding the purity number depending on what type of precious metal it is made out of. The symbol for gold is an octagon shape, like a stretched stop sign with the number stamped in the middle. That shape tells you that the piece is gold, and the number in the middle tells you the purity.

Who knew there was so much to know about gold, even if it is totally pure? Now it’s time to show off your gold expertise in the market and see what you can find!

Testing Your Gold

  • 585 Gold Guide - 14K Gold
    585 Gold, also known as 14K gold one of the most common Karats you'll find. Many jewelers use 585 gold because of its strength and beautiful luster!
  • 750 Gold Guide - 18K Gold
    Interested in buying 750 marked gold? Find out what it means, what symbols you might find associated with it, and anything else that may be relevant.
  • 916 Gold Guide - 22K Gold
    Everything you ever wanted to know about 916, or 22K, marked, gold. What it means, what symbols you might find associated with it, and anything else that may be relevant.

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