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Precious Metals 101: Gold

You’re sitting at a table with a jewelry box that belonged to your grandmother. You open the lid and see all sorts of vintage treasures: tie pins, brooches, sparkly earrings, pocket watches, coins, and a charm bracelet with tiny dangling pendants and baubles. While it all has sentimental value, you can’t help but wonder, “What is this worth?”

That’s where a good understanding of precious metals comes in—and we’re here to deliver with a series devoted to these scarce, sought-after materials. Whether you’re assessing your own collection or hunting for treasure out in the wild, knowing the difference between precious and non-precious metals will come in handy.

The elite Precious Metal Club is made up of three naturally occurring elements: gold, silver, and platinum. Let’s start with good ol’ glamorous gold.

How to Identify Gold

As you know, gold is very valuable and highly sought after. Why? It’s rare, malleable, and durable. Its malleability makes it an excellent material for coins, jewelry, decorative items, and intricate detailing. Since it doesn’t rust, oxidize, or corrode, those items can have quite a lifespan. It doesn’t hurt that gold has been closely intertwined with currency for thousands of years.

The Look 

Naturally yellow in color, the appearance of gold can be altered with the addition of secondary materials. For example, adding zinc or nickel leads to white gold, while adding copper creates the warm hue of rose gold. Additive alloys are used to create a spectrum of colors, from pink to green. Because of this, it’s important to take more than appearance into account when inspecting a suspected gold piece.

Other precious metals include silver, platinum, palladium, and rhodium. These metals have similar properties to gold, such as high density, luster, and resistance to corrosion. However, they all have different colors and melting points.

The Purity

When assessing fine jewelry, it’s essential to understand the gold purity system. The purity of gold is measured in karats (k or kt), which indicate how many parts of gold are in 24 parts of the metal. For example, 24k gold is pure gold, while 14k gold has 14 parts of gold and 10 parts of other metals. Simply put, the higher the purity, the higher the value. Now, how does the average buyer determine this? Luckily, modern gold is often stamped with a hallmark denoting its purity. Take a look at the table below:

Purity Hallmark Gold Content (wt. %) Purity % Hallmark
24k 99+ 990
22k 91.6 916
18k 75.0 750
14k 58.5 585
9k 37.5 375


Keep in mind that not all gold is marked. Antique, custom, and altered pieces may lack identifying marks. That’s why Blue Moon Estate Sales pros are trained to identify and test precious metals to determine their purity and price them appropriately.

You may notice a few other hallmarks as you’re inspecting pieces, specifically when it comes to estate jewelry. It’s common for makers to include a maker’s mark which can be especially exciting to identify. Other marks you may find may indicate that a piece is not solid gold, thus affecting its overall value. Such marks include:

Marking Meaning
GF Gold fill: A base metal with a bonded alloy layer of 10k or more
GP Gold plate: A base metal with a thin layer of gold chemically plated to the surface
GEP Gold electroplate: A base metal with a thin layer of gold electrochemically plated to the surface
RG Rolled gold: A base metal rolled in a thin coating of gold
RGP Rolled gold electroplate
HGE Heavy gold electroplate
925, STERLING or any other silver mark on a gold surface Vermeil: Silver coated in a thick gold alloy layer of 14k or more



Check out these frequently asked questions about shopping for gold jewelry at estate sales!

How can I tell if something is real gold or not?

When shopping for gold at estate sales, yard sales, or garage sales, you'll naturally want to know how to separate costume jewelry from authentic valuable estate pieces. One way to identify gold and other precious metals is to look for markings or stamps on the metal. These precious metal markings indicate the purity, maker, or origin of the material. For example, a marking of 14k means the metal is 14 karat gold. Fakes are usually not stamped, though they may say GP for "gold plated" or GF for "gold filled."

Other ways to identify gold and other precious metals are to use a magnet or an acid test. A magnet can distinguish between real and fake metals, as most precious metals are not magnetic. An acid test determines the purity of the metal, as different acids react differently with different metals. However, these intense tests can damage or ruin the metal if not done properly, so they should be performed with delicate caution by professionals.

What does OL mean?

OL is a common marking on gold jewelry that stands for "overlay." This means that the jewelry has a thin layer of gold on top of another metal, such as copper or brass. Overlay jewelry is also known as gold-filled or rolled gold plate jewelry. Overlay jewelry is different from solid gold jewelry, which has a higher percentage of gold throughout the metal. Overlay jewelry is also different from gold-plated jewelry, which has a thinner layer of gold on top of another metal.

Overlay jewelry has some advantages and disadvantages compared to solid gold or gold-plated jewelry. On one hand, overlay jewelry is more affordable and durable than solid gold or gold-plated jewelry. On the other hand, overlay jewelry can wear off over time and expose the base metal underneath. It can also cause allergic reactions in some people who are sensitive to certain metals.

14k vs 18k Gold: What's the Difference?

14k and 18k are two common types of gold used for jewelry design and other items. As mentioned above, these numbers indicate the purity of the gold in terms of karats. 14k gold has 14 parts of gold and 10 parts of other metals, while 18k gold has 18 parts of gold and 6 parts of other metals.

The difference between 14k and 18k gold lies in their appearance, durability, and price:

  • 18k gold has a richer and more yellow color than 14k gold
  • 18k gold is softer and thus more prone to scratches than 14k gold
  • 18k gold is more expensive than 14k gold

The choice between 14k and 18k gold depends on your personal preference and budget. Some people prefer the higher purity and color of 18k gold, while others prefer the lower cost and durability of 14k gold. The diamond and gold markets constantly fluctuate, so keep an eye on prices.

How can I clean my gold jewelry?

Clean gold jewelry with mild soap, warm water, and a soft cloth. You can also use a special cleaner designed for gold jewelry. Avoid using harsh chemicals, abrasives, or ultrasonic cleaners, as these can damage your gold jewelry.

How can I store my gold jewelry?

Store your gold jewelry by keeping it in a cool, dry, and dark place. You can also use a soft pouch, box, or case to protect jewelry from scratches, dust, and moisture. Avoid storing gold jewelry with other metals or gemstones that can tarnish or scratch it.

What are some tips for shopping for gold at estate sales?

Want to find the good stuff? Some tips for shopping for gold at estate sales are:

  • Know your budget and stick to it
  • Know your size/measurements
  • Know your karats and markings
  • Carefully assess value and quality
  • Don't be afraid to haggle
How can I sell my unwanted or broken gold jewelry?

You can sell your unwanted or broken gold jewelry by holding an estate sale, taking it to a reputable jeweler, a pawn shop/flea market, or a cash-for-gold company. You can also sell your unwanted or broken gold jewelry through online platforms, though handling the listing and shipping might be a hassle.

Always exercise caution when selling unwanted or broken gold jewelry online as there may be scams or frauds involved. Check the buyer's reputation, feedback, and ratings before making a deal.


Finding Gold Jewelry & Collectibles at Estate Sales

Estate sales are great places to find gorgeous vintage jewelry and other pre-owned collectibles for a fair price. Here's how to find gold jewelry and collectibles at estate sales:

  • Do your research before attending an estate sale. Look for online listings or ads that mention what kinds of items will be sold at the estate sale. Look for keywords such as "gold", "jewelry", "coins", "collectibles", etc.
  • Arrive early to get the best selection and deals. Estate sales usually start early in the morning and last for a few hours or days. The earlier you arrive, the more chances you have to find what you are looking for.
  • Bring cash. Some estate sales only accept cash as payment, so make sure you have enough cash on hand to buy what you want.
  • Bring tools to test the items such as a magnifying glass and a magnet. Before buying estate jewelry, inspect and test the items for authenticity and purity.
  • Negotiate with the sellers if possible. Estate sales are often run by professional companies or family members who want to sell the items quickly and clear out the space. You may be able to negotiate the price down if you buy multiple items, offer cash, or discover flaws or damages in the items.

Shop for Antique Jewelry with Help from Blue Moon Estate Sales

Gold is one of the most sought-after and valuable metals in the world. It has been used for jewelry, coins, art, and technology for thousands of years. Now that you’re equipped with some valuable knowledge about how to identify precious metals and how to go about buying gold during the estate sale process, you may want to take a look through your own collection. If you have any gold coins or jewelry you're looking to rehome, don't just pawn them off. Give us a shout. We can discuss your best options, including consignment.

We take our estate sale treasures seriously, especially when it comes to precious metals. We love nothing more than the thrill of the hunt, so if you're looking to strike gold without spending a fortune, head out to a Blue Moon sale near you. We'll see you there!