Gold-Plated, Gold-Filled, and Vermeil: What's the Difference? A Guide to Identifying Jewelry with No | Gu Jin Jian Bao

"Gold-colored"doesn't mean"pure gold"– plating, gold-filling, and gold-over-silver are surface treatment techniques that can make jewelry with copper or silver bases look identical to real gold. However, in the buyback market, the gold content of these items is almost zero, meaning they have virtually no buyback value. How can you distinguish them initially without sending them for professional testing? Here are a few practical methods.

1. Gold Plated (GP): A Very Thin Layer of Gold on the Surface

The English abbreviation for gold plating is GP, and common markings on jewelry include "14KGP," "18KGP," and "Gold Plated." The principle involves using electrolysis to deposit an extremely thin layer of gold onto the surface of another metal (usually copper, zinc alloy, or stainless steel).

• Extremely thin. The gold plating layer is usually only 0.18 to 15 micrometers thick, almost invisible to the naked eye.
• Very low gold content. The overall gold content of the entire piece of jewelry is about 0.05%, which means the gold by weight is negligible.
• Prone to fading. After wearing for a period, the base color (mostly reddish-copper or silver-white) will show through at the edges and raised areas.
• Almost no buyback value. Even if melted, the recoverable amount of gold is far less than the cost of appraisal and labor, so most recyclers will not accept it.

Another common scenario: jewelry engraved with"925"but appearing gold-colored – this is actually silver jewelry with a thin layer of gold plating (commonly known as"gold-plated silver"). When Bought back, it can only be valued as pure silver, not as gold.

2. Gold Filled (GF): Gold Foil Pressed Onto Metal

Gold-filled items are a step above gold-plated, but fundamentally different from karat gold.

• Manufacturing process. A thicker layer of gold foil (usually 14K or 12K) is pressed onto the surface of another metal using a high-temperature forging process, creating a "sandwich-like" structure.
• Gold content. The U.S. Federal Trade Commission requires that 14K gold-filled products contain at least 1/20 (i.e., 5%) gold by total weight.
• Markings. Jewelry may have markings like "14K GF" or "1/20 14K GF."
• Low buyback value. Although the gold content is higher than gold-plated items, because the gold layer and base metal are difficult to perfectly separate, most professional recyclers do not independently value gold-filled pieces, and acceptance depends on the purity.

3. Gold Over Silver and Injected/Hollow Gold: The Most Common High-Fidelity Fakes in Recent Years

With high gold prices in recent years, counterfeiting techniques have also advanced. The following two types are so convincing that even industry insiders need instruments to tell them apart:

1. Gold Over Silver

The appearance is extremely similar to real gold, and some even include fake brand hallmarks and inspection certificates, making it almost impossible to distinguish with the naked eye.

• The gold content can be as low as about 0.3%, but the surface looks identical to 24K jewelry.
• The cost is very low (possibly only a dozen dollars per gram), but it's sold at real gold prices in the second-hand market, yielding huge profits.
• Traditional methods like weighing or burning are extremely difficult to use for identification. XRF non-destructive testing is the most direct diagnostic tool.

2. Injected / Hollow Gold

Even more deceptive, mainly found in hollow items such as thick chains, hollow bracelets, and hollow gold plaques.

• Counterfeiters exploit the hollow structure of the jewelry by injecting liquid inside (and even adjusting its density to closely match gold).
• The appearance, markings, and initial weight pass inspection, but once melted, the weight can "shrink" by two or three grams or even more.
• When customers trade, if they only pay based on surface weight, they can lose a significant amount of money.

3. Tungsten Core Fake Gold Bars

Tungsten's density (19.25 g/cm³) is very close to gold's (19.32 g/cm³), so fake gold bars with tungsten cores can even pass water displacement tests. Identification methods:

• XRF surface inspection. The composition of the surface gold layer can be read, but it needs to be combined with density measurement to determine the internal composition.
• Ultrasonic testing. For high-value gold bar transactions, it is recommended to request additional ultrasonic and corner-cutting tests.

4. Value Range of Real Karat Gold: How 18K, 14K, and 9K are Calculated

Many customers see the"K"on jewelry and assume it has no value, but in fact, real karat gold is a gold alloy, containing a significant proportion of gold, and is a precious metal with buyback value.

Karat Gold Type	Gold Purity (per mille)	Gold Content Ratio	buyback value
24K Gold	999‰	99.9%	Highest buyback price, based on current gold price
22K Gold	916‰	91.6%	High gold content, common in Indian and Middle Eastern jewelry
18K Gold	750‰	75.0%	Good hardness, main choice for high-end jewelry in Hong Kong
14K Gold	585‰	58.5%	Still has buyback value, common in European and American jewelry
9K Gold	375‰	37.5%	Relatively low gold content, some recyclers accept it
Gold Plated (KGP / GP)	Approx. 0.05%	Extremely low	Virtually no buyback value

The calculation is straightforward: actual received price = current gold price × weight × gold content ratio. For example, an 18K gold item will be worth 75% of the same weight in 24K pure gold. Even broken, tarnished, or deformed K gold jewelry, as long as its purity is confirmed, can still be accepted proportionally. For all cash-out procedures and negotiation tips, the Practical Guide to Gold Buyback has a complete version.

5. Preliminary Checks You Can Do at Home (Before Selling Gold)

Before taking it for official appraisal, here are a few simple actions you can do yourself:

1. Check for markings. Use a magnifying glass to check the inside, clasp, and edges of the jewelry for engravings. "999," "9999," "Au750," "K18," "585" indicate real K gold; "KGP," "GP," "GF," "1/20" indicate gold-plated or gold-filled.
2. Check for wear. If the base color (reddish-copper, silver-white) is visible at raised areas, clasps, or the inside of rings, it's likely a gold-plated item where the plating has worn through.
3. Magnet test (rough screening). Real gold and pure silver are not attracted to magnets. If a magnet strongly attracts the item, it likely has an iron-based core and is definitely not pure gold. However, not being attracted to a magnet doesn't necessarily mean it's gold (copper and aluminum are also not magnetic).
4. Sound test. Gently drop the jewelry onto a hard surface. Real gold has a dull, thudding sound; gold-plated items usually produce a clear, ringing sound. This method is only for rough screening.
5. Absolutely do not use fire. The fire test is an outdated method that can damage the jewelry's structure and may not distinguish gold-over-silver. The safest way to identify real gold is to use XRF non-destructive testing.

6. Why Professional Appraisal is Still Necessary?

Relying solely on sight, magnets, and sound can only rule out the most obvious gold-plated items. When dealing with genuine high-fidelity fakes (e.g., gold-over-silver, injected gold, tungsten core gold bars), instruments are necessary for accuracy:

1. XRF non-destructive testing. Uses an X-ray fluorescence spectrometer to read the metal composition, determining the percentages of gold, silver, and copper within 30–60 seconds, with an error margin within ±0.1%, without any damage to the jewelry.
2. Density measurement. Uses Archimedes' principle to measure density, helping to identify if the gold bar contains other metals in its core. For high-value gold bar transactions, dual testing is essential.
3. Non-metal accessory handling. For real gold jewelry set with diamonds, jade, or other gemstones, the non-metal parts are usually not included in the gold weight. The gold portion is weighed separately and not confused.

For common traps in the Hong Kong market, along with price-cutting tactics, the Common Gold Buyback Traps in Hong Kong article provides a complete overview. It's recommended to read it before selling gold.

7. Frequently Asked Questions

Q1: My grandmother's gold chain has a black film on the outside. Is it gold-plated?
Not necessarily. Real K gold can tarnish if unworn for a long time, or due to grease or copper oxide. An XRF test can easily tell the difference.

Q2: Can a gold-colored item with a "925" mark be sold as gold?
No. "925" is the standard for silver jewelry (92.5% silver content), and the gold color is merely surface plating. It can be valued as silver jewelry, but not as gold.

Q3: What does "PT950" engraved on a wedding ring mean?
PT950 stands for 95% platinum. It is another precious metal, not equivalent to K gold, and not within the scope of gold Buyback. However, it can be valued separately at the platinum purchase price.

Q4: Small gold-plated items are worthless, can I just throw them away?
Before throwing them away, you can take a picture of them together and send it to us for a combined assessment. If there truly is no buyback value, we will let you know directly.

8. Contact Information

Real gold, gold-plated, gold-filled, gold-over-silver, and injected gold items often look extremely similar, but their actual value can differ a hundredfold. Getting a non-destructive test before heading out will at least save you a wasted trip. Gu Jin Jian Bao offers free home visits and on-the-spot XRF testing across Hong Kong, Kowloon, and the New Territories:

• WhatsApp： 98342057
• WeChat： john19998
• Phone： 852-98342057

Send a clear photo, and we'll reply with an assessment within half an hour. Appraisal is free, and you're not obligated to sell if you're not satisfied.