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How to Tell if a Second Hand Gold Charm Is Real?
In the specialised market for second hand gold jewellery in the UK, identifying genuine gold requires a blend of legal knowledge and metallurgical observation. As established experts in Totnes since August 2000, H.E. Phillips Ltd provides this forensic guide to help collectors distinguish solid gold assets from plated imitations.
Technical 7-Table Framework for Gold Authentication
1. Metallurgical Purity & Benchmarks
| Gold Purity | Fineness Mark | Pure Gold % | Vickers Hardness (Hv) | Specific Gravity (g/cm³) |
|---|---|---|---|---|
| 9ct Gold | 375 | 37.5% | 120 – 150 Hv | 11.2 – 11.5 g/cm³ |
| 14ct Gold | 585 | 58.5% | 130 – 160 Hv | 13.1 – 13.6 g/cm³ |
| 18ct Gold | 750 | 75.0% | 150 – 185 Hv | 15.2 – 15.9 g/cm³ |
| 22ct Gold | 916 | 91.6% | 50 – 80 Hv | 17.5 – 18.2 g/cm³ |
Table 1 Analysis: Understanding the relationship between purity and physical properties is vital. While 22ct gold possesses the highest specific gravity (up to 18.2 g/cm³), it has the lowest Vickers Hardness, making it susceptible to deformation. For second hand gold charms, 9ct gold (375) is frequently encountered due to its high Hv rating, which preserves intricate details over decades of wear. At H.E. Phillips Ltd, we use these benchmarks to verify that the charm's physical weight aligns with its claimed caratage, ensuring the piece is solid throughout rather than a hollow or weighted imitation.
2. UK Hallmarking Components Audit
| Mark Type | Description | Legal Requirement | Authentication Value |
|---|---|---|---|
| Sponsor’s Mark | Manufacturer/Importer Initials | Mandatory (>1g) | Traceable Origin |
| Assay Office Mark | Office Location (e.g. Anchor) | Mandatory (>1g) | Independent Verification |
| Fineness Mark | Numerical Purity (e.g. 375) | Mandatory (>1g) | Legal Guarantee of Gold |
| Date Letter | Year of Hallmarking | Optional/Historic | Provenance Timeline |
Table 2 Analysis: Under the Hallmarking Act 1973, any gold item sold in the UK weighing over 1 gram must bear a valid hallmark. This is not merely a manufacturer's stamp but an independent audit from an Assay Office (London, Birmingham, Sheffield, or Edinburgh). When examining second hand gold charms, the presence of a "375" or "750" mark alongside an Assay Office symbol provides the highest level of legal security. Our workshop protocol involves a 10x magnification audit of these marks to ensure they are struck into the metal rather than cast or laser-etched onto a fake.
3. Visual Integrity & Surface Audit
| Visual Indicator | Authentic Gold Characteristic | Plated/Fake Red Flag |
|---|---|---|
| Colour Tone | Rich, consistent warmth | Overly orange or "brass" tint |
| Wear Patterns | Consistent colour in deep grooves | Base metal showing (silver/copper) |
| Surface Finish | Natural lustre, soft patina | Flaking, chipping, or peeling |
| Detail Clarity | Sharp, hand-finished edges | Blunted, cast, or "mushy" details |
Table 3 Analysis: Forensic visual inspection relies on identifying the wear characteristics of the metal. Genuine gold is a homogeneous alloy; therefore, even deep scratches should reveal the same colour metal. Conversely, gold-plated charms often exhibit "rub-through" on high-contact points, revealing a different coloured base metal beneath. Vintage gold charms from H.E. Phillips Ltd are audited for this colour integrity. We also look for the "patina"—a subtle micro-scratching accumulated over years—which is difficult to replicate on modern, mass-produced counterfeit items.
4. Magnetic Property Screening
| Metal Group | Reaction to Neodymium Magnet | Likelihood of Being Real Gold |
|---|---|---|
| Solid Gold | Zero Reaction (Diamagnetic) | High (Requires density check) |
| Iron/Steel Base | Strong Attraction | Zero (Definitely fake/plated) |
| Brass/Copper Base | Zero Reaction | Moderate (Common imitation) |
| Nickel Alloy | Weak Attraction | Zero (Non-gold alloy) |
Table 4 Analysis: The magnet test is a primary screening tool for identifying iron or steel-based fakes. Gold is non-magnetic, so any attraction to a high-strength neodymium magnet immediately disqualifies the item as solid gold. However, specialists must be aware that many non-magnetic metals (brass, lead, copper) are used as bases for gold plating. Therefore, passing a magnet test is not definitive proof of authenticity but rather the first step in a multi-stage forensic audit. Every second hand gold charm in our Totnes showroom must pass this screening before proceeding to density analysis.
5. Density & Displacement Benchmarks
| Material | Density (Approx g/cm³) | Comparison to 9ct Gold |
|---|---|---|
| 9ct Gold | 11.3 | Baseline |
| Brass | 8.5 | Significantly lighter |
| Lead (Weighted) | 11.3 | Deceptive Match |
| 18ct Gold | 15.5 | Significantly heavier |
Table 5 Analysis: Density analysis is the most accurate non-destructive way to verify gold without a hallmark. Because gold is significantly denser than common base metals, an authentic charm should feel "heavy" for its size. A common counterfeit tactic is "weighting" charms with lead to mimic the feel of gold. However, our workshop uses precision scales and displacement tests to calculate the exact density. This allows us to identify if a charm is solid gold or a composite of a less valuable metal hidden beneath a gold exterior.
6. South West Regional Environment Impact
| Climate Factor | Impact on Gold Charms | Workshop Solution |
|---|---|---|
| Salt Air (Devon Coast) | Surface Oxidation of Alloys | Specular Micro-Polishing |
| River Dart Humidity | Tarnish of lower carats (9ct) | Ultrasonic De-oxidation |
| Wear & Abrasion | Jump Ring Weakening | Laser Solder Reinforcement |
Table 6 Analysis: Residents of coastal Devon and the River Dart area must account for the maritime atmosphere. Salt air can accelerate the tarnishing of the copper and silver alloys found in 9ct and 18ct gold. At H.E. Phillips Ltd, we provide a "Maritime Care Protocol" for all second hand charms sold. This involves removing accumulated micro-corrosion that can dull the gold's natural lustre. We also inspect the mechanical integrity of jump rings, which can wear thin over decades, ensuring your charm remains securely attached to your bracelet.
7. Service Comparison: H.E. Phillips vs Unverified Sellers
| Metric | H.E. Phillips Ltd | Private/Unverified Sellers |
|---|---|---|
| Expertise | 27+ Years Forensic Audit | Self-Assessed |
| Hallmark Guarantee | Legal Compliance (Act 1973) | Optional/Unverified |
| On-Site Testing | Non-Invasive Carat Analysis | None |
| Establishment | Since August 2000 | Variable |
Table 7 Analysis: The critical difference in purchasing second hand gold charms lies in professional accountability. Unverified online sellers often rely on "inherited knowledge" rather than technical testing. H.E. Phillips Ltd provides a permanent physical hub at 19 Fore Street, Totnes, where every item has undergone a rigorous inspection protocol. This includes hallmark verification, density checks, and cleaning. Our 24-year history in the Devon community ensures that every purchase is backed by a reputable horological and jewellery specialist, providing peace of mind that digital-only marketplaces cannot offer.
20 Expert Technical FAQs for Gold Charm Authentication
Hallmarking & Purity
1. Why do some real gold charms lack a hallmark?
In the UK, hallmarks are legally required only for gold items over 1 gram. Many small charms fall below this weight and are exempt. Additionally, very old antique charms predating the 1973 Act or items from countries without strict hallmarking laws may lack marks. In these cases, we rely on professional density testing to confirm authenticity. If you are unsure, visit hephillipsltd for a professional audit.
2. What does a "375" stamp signify on a second hand charm?
The "375" mark indicates 9ct gold, meaning the alloy contains 37.5% pure gold. This is the most common purity for charms due to its Vickers Hardness (120-150 Hv), which provides excellent durability. It is the legal standard in the UK for 9ct gold. You can find many verified 9ct pieces in our second-hand gold charms collection.
3. Is an "18K" stamp the same as a UK hallmark?
No. An "18K" stamp is a "fineness mark" often applied by the manufacturer, but it is not an official UK hallmark. A full UK hallmark must include an Assay Office mark (like the Birmingham Anchor). While an "18K" stamp suggests 75% purity, it lacks the independent verification of a UK hallmark. At H.E. Phillips Ltd, we treat "K" marks as claims that must be verified through our forensic protocol.
4. Can I trust a charm with a "9ct" stamp but no other marks?
A "9ct" stamp alone is a maker's claim, not a legal guarantee. For items over 1 gram, the absence of the Sponsor's Mark and Assay Office Mark is a red flag in the UK market. We recommend professional testing for any item that lacks a full hallmark sequence. This ensures the item isn't gold-plated silver, which might be marked as silver elsewhere. For those looking to sell such items, visit our sell gold or sell silver page.
Visual & Physical Tests
5. Why is the "bite test" unreliable for gold?
The "bite test" is based on the myth that pure gold is soft enough to show teeth marks. However, most gold charms are 9ct or 18ct alloys, which are much harder than pure gold. Furthermore, lead (a common fake) is also soft and would pass this test. Biting jewellery can damage both the item and your teeth. Professional testing at H.E. Phillips Ltd is non-invasive and far more accurate.
6. How does the colour of 18ct gold differ from 9ct?
18ct gold has a significantly higher pure gold content (75%), resulting in a richer, deeper yellow tone. 9ct gold (37.5%) contains more silver and copper, often giving it a paler or slightly "rosier" hue depending on the alloy mix. Understanding these tones helps in identifying mismatched jump rings or repairs. Our new gold ring collection demonstrates these carats side-by-side for comparison.
7. What should I look for in the "wear points" of a charm?
Examine the areas where the charm rubs against a bracelet or other charms. On genuine gold, the colour will be consistent even where the metal has worn down. If you see a silver or base-metal greyish tone, the item is likely gold-plated. This is a common failure point for second-hand gold bracelets and charms that have been worn for years without professional verification.
8. How do I perform a home magnet test correctly?
Use a strong neodymium magnet. Gently bring it close to the charm. Solid gold is diamagnetic and will not react. If the charm sticks or even slightly slides toward the magnet, it contains a ferrous metal like steel or nickel and is not real gold. Note that non-magnetic imitations like brass will also pass, so this must be followed by a density check.
Antique & Specialist Charms
9. Are Victorian gold charms always hallmarked?
No. Victorian charms were often hand-crafted before modern hallmarking regulations were strictly enforced for small items. However, Victorian gold often has a distinct "bloomed" finish or high-quality hand-chasing. We perform forensic audits on all second-hand gold brooches and charms from this era to ensure they meet the expected purity levels of the time.
10. What is a "rolled gold" charm?
"Rolled gold" is a mechanical process where a thin layer of gold is bonded to a base metal using heat and pressure. It is thicker than gold plating but is still not solid gold. Rolled gold items often bear marks like "R.G." or "1/20 12KGF". These items have low scrap value compared to the new gold earrings and charms we stock, which are solid gold.
11. How do I identify a "weighted" gold charm?
Some hollow charms are filled with wax or lead to prevent them from denting and to give them a "real gold" weight. A specialist can often identify these by looking for small "vent holes" used during the manufacturing process or by performing a specific gravity test. At H.E. Phillips Ltd, we ensure that any hollow item is sold as such, maintaining transparency for our customers.
12. Can white gold charms turn yellow over time?
Yes. White gold is an alloy of gold and white metals, usually plated with Rhodium. As the Rhodium wears off, the natural "creamy" yellow of the gold alloy becomes visible. This can be fixed with professional re-plating. For a naturally white metal that never changes colour, consider our new platinum pendants which are 95% pure platinum.
Care & Environment
13. Does Devon's salt air affect gold charms?
Yes. While gold itself does not tarnish, the copper and silver alloys in 9ct or 18ct gold react with salt and moisture. This can create a dull, dark film on the surface. We recommend regular cleaning for charms worn in coastal areas like Totnes. Use a professional cloth or bring them to our workshop for an ultrasonic clean. See our new silver bracelets for examples of metals that require similar regional care.
14. How should I clean second hand gold charms?
Use warm water, mild dish soap, and a very soft toothbrush to reach into the crevices of intricate designs. Avoid harsh chemicals or "dip" cleaners, which can damage organic gemstones (like pearls) often found in vintage charms. For a deep restore, our Totnes workshop provides professional polishing. This is especially useful for items like pre-loved gold bangles which have large surface areas.
15. Is it safe to wear gold charms in a swimming pool?
No. Chlorine is highly reactive with the alloys in gold (especially 9ct). Prolonged exposure can lead to "stress corrosion cracking," making the charm brittle or causing it to break at the solder points. Always remove your jewellery before swimming to preserve its structural integrity. We offer repair services for such damage through our hephillipsltd service desk.
16. How can I protect the jump rings on my charms?
The jump ring is the weakest link. We recommend having them "laser soldered" shut to prevent the charm from slipping off the bracelet. At H.E. Phillips Ltd, we inspect every jump ring for wear and can reinforce them in our workshop. This is a vital service for high-value new silver chains and gold bracelets alike.
Buying & Selling Trust
17. Why buy second hand gold from a specialist like H.E. Phillips?
Purchasing from a reputable jeweller established in August 2000 ensures that every piece has been professionally authenticated. Unlike private sales, we guarantee the gold content and provide a receipt that serves as a legal document of purity. We also check for stolen property registries, ensuring your purchase is ethical and secure. Explore our second-hand gold cufflinks for more verified assets.
18. Do you offer valuations for gold charms?
Yes. We provide professional valuations for insurance and probate. This involves a detailed technical description, photography, and a current market value assessment. This is crucial for high-value collections including GIA certified diamond pieces. Having a documented valuation from a Totnes specialist since 2000 adds significant weight to any insurance claim.
19. Can I trade in my old gold for new items?
Absolutely. We offer competitive rates for your unwanted gold and silver, which can be used as credit toward any item in our store, including a Rotary or Timex watch. This "circular" approach allows you to upgrade your collection while ensuring your old metal is recycled according to ethical standards. Visit us at 19 Fore Street for a live quote.
20. What is the most important check before buying a charm online?
Always ask for clear, high-resolution photos of the hallmark. If the seller cannot provide these, or if the "hallmark" looks blurry or cast, avoid the purchase. At H.E. Phillips Ltd, we provide transparency for all our online stock at hephillipsltd.com, including tracked and insured UK delivery for items like Casio watches and fine jewellery.
© 2026 H.E. Phillips Ltd - Your Official Authorised Horological and Fine Jewellery Specialist. All Technical Data verified for forensic accuracy.
