How to Test if Gold is Real at Home
With gold prices at record highs, knowing how to verify authenticity is more important than ever. This guide explains 7 testing methods you can use at home, the science behind each test, and when you need professional verification.
Important: No Single Test is Definitive
Sophisticated fakes can pass individual tests. Always combine multiple methods and for high-value items, seek professional XRF testing. Home tests can indicate likely fakes but cannot guarantee authenticity with 100% certainty.
Quick Reference: Which Test to Use
| Test | Reliability | Difficulty | Damages Item? | Best For |
|---|---|---|---|---|
| Visual/Hallmarks | Medium | Easy | No | First check on any item |
| Magnet Test | Low | Easy | No | Ruling out cheap fakes |
| Density Test | High | Medium | No | Solid items without gems |
| Vinegar Test | Medium | Easy | No | Quick screening test |
| Ceramic Scratch | Medium | Easy | Yes | Suspected fakes you don't mind scratching |
| Acid Test | High | Hard | Yes | Determining exact purity |
| Ping Test | Medium | Easy | No | Coins and bars only |
Detailed Testing Methods
⚗️ The Science
UK law requires gold items over 1g to be hallmarked by an assay office. These stamps verify the gold has been independently tested. Visual inspection can also reveal plating wear-through.
What You Need
- Magnifying glass or 10x loupe
- Good lighting
Step-by-Step
- 1Find the hallmark - check inside rings, near clasps, on the back of pendants
- 2Look for a 3-digit number: 375 (9ct), 585 (14ct), 750 (18ct), 916 (22ct), 999 (24ct)
- 3Check for an assay office mark: leopard's head (London), anchor (Birmingham), rose (Sheffield), castle (Edinburgh)
- 4Examine edges, clasps, and high-wear areas for discolouration or a different metal showing through
How to Interpret Results
Valid UK hallmarks are a strong indicator of genuine gold. However, hallmarks can be forged, so combine with other tests. Wear-through revealing a different colour metal indicates plating.
Limitations
- ⚠️ Hallmarks can be faked (though this is illegal)
- ⚠️ Items under 1g don't require hallmarking
- ⚠️ Foreign gold may have different marking systems
- ⚠️ Worn items may have illegible hallmarks
⚗️ The Science
Gold is diamagnetic - it's not attracted to magnets and shows very weak repulsion. Ferromagnetic metals like iron and nickel are strongly attracted. If an item sticks to a magnet, it contains these metals and isn't solid gold.
What You Need
- Strong neodymium magnet (not a fridge magnet)
Step-by-Step
- 1Get a strong neodymium magnet (available online cheaply)
- 2Hold the magnet close to your gold item
- 3Observe any attraction or movement
How to Interpret Results
Strong attraction = definitely not solid gold. No attraction = possible gold, but not proof (copper, brass, and lead are also non-magnetic). This test rules out fakes but doesn't confirm authenticity.
Limitations
- ⚠️ Many fake materials (copper, brass, lead, aluminium) are also non-magnetic
- ⚠️ Gold-plated items with non-magnetic cores will pass
- ⚠️ Clasps and springs may contain magnetic metals even on real gold jewelry
- ⚠️ Only rules out iron/nickel-based fakes
⚗️ The Science
Gold is one of the densest metals at 19.3 g/cm³. This is extremely difficult to fake - common counterfeit materials have much lower densities. By measuring weight and water displacement, you can calculate density precisely.
What You Need
- Digital scale (0.1g accuracy)
- Glass of water
- String or thin wire
- Calculator
Step-by-Step
- 1Weigh the item dry and record the weight in grams (W₁)
- 2Fill a glass with water and place it on the scale, then zero/tare the scale
- 3Suspend the item fully in the water using string (don't let it touch the bottom or sides)
- 4Record the weight shown on the scale - this equals the water displaced (W₂)
- 5Calculate density: Density = W₁ ÷ W₂
How to Interpret Results
Compare your result to the expected density for that purity. Pure 24ct gold = 19.3 g/cm³, 22ct = 17.7-17.9, 18ct = 15.2-15.9, 14ct = 13.0-14.5, 9ct = 11.3-12.7. Results within 5% of expected values indicate genuine gold.
Limitations
- ⚠️ Hollow items or those with gemstones give inaccurate results
- ⚠️ Requires reasonably accurate scales
- ⚠️ Small items have higher measurement error
- ⚠️ Tungsten has similar density to gold (extremely rare in fakes but possible)
⚗️ The Science
Gold is a 'noble metal' - chemically inert and resistant to corrosion. Vinegar (acetic acid) doesn't react with gold but will react with base metals like copper, zinc, and iron, causing discolouration or bubbling.
What You Need
- White vinegar
- Glass or ceramic dish
- Cotton bud (optional)
Step-by-Step
- 1Clean the item to remove dirt or oils
- 2Place the item in a glass dish or apply vinegar directly with a cotton bud
- 3Cover the item with white vinegar
- 4Wait 15 minutes
- 5Observe any colour change or reaction
How to Interpret Results
No change = consistent with real gold. Discolouration, bubbling, or green tinge = base metals reacting, indicates fake or heavily plated gold. The reaction happens because vinegar dissolves the oxide layer on base metals.
Limitations
- ⚠️ Low-carat gold (9ct) contains 62.5% base metals but usually won't react noticeably
- ⚠️ Gold plating thick enough may protect base metal temporarily
- ⚠️ Test doesn't work on all fake alloys
- ⚠️ Not definitive proof on its own
⚗️ The Science
When gold is dragged across unglazed ceramic, it leaves a gold-coloured streak because it's softer than the ceramic. Many fake gold alloys leave black, grey, or greenish marks instead.
What You Need
- Unglazed ceramic tile or plate (the rough underside works)
Step-by-Step
- 1Find an unglazed ceramic surface (the bottom of a ceramic plate or tile)
- 2Firmly drag the gold item across the surface
- 3Examine the colour of the streak left behind
How to Interpret Results
Gold streak = consistent with real gold. Black or grey streak = likely pyrite ('fool's gold') or other fake material. Note: this test can scratch your item.
Limitations
- ⚠️ Can scratch and damage genuine gold items
- ⚠️ Gold-plated items may leave a gold streak initially
- ⚠️ Doesn't determine purity, only that gold is present
- ⚠️ Some gold alloys may leave slightly different coloured streaks
⚗️ The Science
Nitric acid dissolves most metals but not gold. Testing kits contain acids calibrated for different purities - if a scratch dissolves under a specific acid, the gold is below that purity. Professional method used by many dealers.
What You Need
- Gold testing acid kit (different acids for different carats)
- Black touchstone
- Safety equipment (gloves, goggles)
Step-by-Step
- 1Put on safety gloves and goggles
- 2Rub the gold firmly on the black touchstone to leave a visible mark
- 3Apply the lowest carat acid (usually 9ct) to the mark
- 4If the mark remains, test with higher carat acids until it dissolves
- 5The highest acid that doesn't dissolve the mark indicates the purity
How to Interpret Results
Mark dissolves in 9ct acid = below 9ct (not UK legal gold). Mark survives 18ct acid but dissolves in 22ct acid = 18ct gold. Mark survives all acids = 22ct or higher.
Limitations
- ⚠️ Requires purchasing testing kit (£10-30)
- ⚠️ Acids are corrosive - safety precautions essential
- ⚠️ Leaves a small scratch on the item
- ⚠️ Heavy gold plating can give false positives
- ⚠️ Requires some practice to interpret correctly
⚗️ The Science
Gold has a distinctive acoustic signature. When a gold coin or bar is struck, it produces a long, high-pitched ringing sound due to gold's elasticity and density. Fake metals produce a duller, shorter sound.
What You Need
- Another piece of metal or coin to strike against
Step-by-Step
- 1Hold the gold coin or bar loosely on your fingertip (don't grip it)
- 2Gently tap it with another coin or small metal object
- 3Listen to the sound produced
How to Interpret Results
Long, high-pitched ring that sustains for 1-2 seconds = consistent with gold. Dull thud or short clunk = likely not gold. Works best with coins and bars; less reliable for jewelry.
Limitations
- ⚠️ Only works well with coins and bars, not jewelry
- ⚠️ Requires some experience to recognise the 'right' sound
- ⚠️ Alloyed gold (9ct, 14ct) sounds different from pure gold
- ⚠️ Some fakes are designed to pass this test
Density Reference Tables
The density test is the most reliable home method because gold's density is extremely difficult to fake. Use these tables to interpret your results.
| Carat | Fineness | Density (g/cm³) |
|---|---|---|
| 24ct | 999 | 19.3 |
| 22ct | 916 | 17.7 - 17.9 |
| 18ct | 750 | 15.2 - 15.9 |
| 14ct | 585 | 13.0 - 14.5 |
| 9ct | 375 | 11.3 - 12.7 |
| Material | Density (g/cm³) | Notes |
|---|---|---|
| Brass | 8.4 - 8.7 | Common in fake jewelry |
| Copper | 8.9 | Used in gold plating base |
| Lead | 11.3 | Similar to 9ct - can fool basic tests |
| Tungsten | 19.3 | Same as gold - rare but sophisticated fakes |
| Steel | 7.8 | Magnetic - fails magnet test |
Warning: Tungsten Fakes
Tungsten has almost identical density to gold (19.3 g/cm³), making it the material of choice for sophisticated fakes. Tungsten-core gold bars have been discovered. The density test cannot detect these. For high-value bars, professional XRF or ultrasound testing is essential.
When to Seek Professional Testing
- ✓ Low-value items you're curious about
- ✓ Initial screening before selling
- ✓ Checking inherited jewelry
- ✓ Ruling out obvious fakes
- ✓ Educational purposes
- ! Items worth over £500
- ! Gold bars (tungsten fake risk)
- ! Before major purchases
- ! Insurance valuations
- ! When home tests give conflicting results
XRF (X-Ray Fluorescence) Testing
The gold standard for testing. Non-destructive, determines exact metal composition in seconds. Available at assay offices, reputable jewellers, and gold dealers. Typical cost: £10-30 per item.
UK Assay Offices
The four UK assay offices (London, Birmingham, Sheffield, Edinburgh) offer testing services. They can also hallmark unhallmarked items. Most authoritative testing available.
Reputable Gold Dealers
Most dealers will test items for free if you're considering selling to them. Find dealers in your area using our dealer directory.
Red Flags: Signs of Fake Gold
Visual Warning Signs
- !Discolouration or green/black marks
Base metals oxidising beneath the surface
- !Different colour visible on edges or clasps
Gold plating wearing through to base metal
- !No hallmark on items that should have one
UK law requires hallmarks on gold over 1g
- !Blurry or poorly defined hallmarks
Genuine hallmarks are crisp and clear
Behavioural Warning Signs
- !Price too good to be true
Gold has a market price - big discounts are suspicious
- !Seller refuses testing
Legitimate sellers welcome verification
- !Leaves green marks on skin
Copper oxide from base metal - not real gold
- !Feels unusually light
Gold is dense - lightness suggests base metal
Frequently Asked Questions
Does real gold stick to a magnet?
No, real gold is not magnetic and will not stick to a magnet. If your gold item is attracted to a strong magnet, it contains ferromagnetic metals like iron or nickel and is not solid gold. However, passing the magnet test doesn't prove gold is real - many fake metals like copper and brass are also non-magnetic.
Can you test gold with vinegar?
Yes, vinegar can help test gold. Apply a few drops of white vinegar to the item and wait 15 minutes. Real gold won't change colour or react because gold is chemically inert. Fake gold or gold-plated items may discolour, bubble, or develop a greenish tinge as the vinegar reacts with base metals.
How can you tell if gold is real by looking at it?
Look for official UK hallmarks (375, 585, 750, 916, 999) which indicate tested gold. Check edges, clasps, and high-wear areas with a magnifying glass for discolouration or a different metal showing through. Real gold has a consistent warm yellow colour (or white/rose depending on alloy) and doesn't tarnish or turn green.
What is the most accurate way to test gold at home?
The density test is the most accurate home method. Gold has a very high density (19.3 g/cm³ for pure gold) that is extremely difficult to fake. By weighing the item and measuring its water displacement, you can calculate density and compare it to known gold values. However, professional XRF testing remains the gold standard.
Will fake gold turn green?
Fake gold or very low-quality gold-plated items can turn green or leave green marks on skin. This happens when copper in the base metal oxidises. Real solid gold (even 9ct) should not turn green, though it may tarnish slightly over time. Green discolouration is a strong indicator of fake or plated gold.
How do professionals test gold?
Professionals use X-ray Fluorescence (XRF) analysers which determine the exact composition of metals without damaging the item. XRF machines cost thousands of pounds but provide definitive results in seconds. Assay offices and reputable dealers use this technology. Some also use electronic gold testers or acid testing kits.
Know Your Gold's Value
Once you've verified your gold is real, find out what it's worth today
Related Guides
Learn to read hallmarks, identify assay office symbols, and understand purity marks.
Read Guide →Understand 9ct vs 18ct vs 24ct, what the numbers mean, and how purity affects value.
Read Guide →Step-by-step guide to selling your gold jewelry and getting the best price.
Read Guide →Sources and References
Gold density and physical properties: CRC Handbook of Chemistry and Physics.
UK hallmarking requirements: The Hallmarking Act 1973. Source:legislation.gov.uk
Assay office testing information:London Assay Office
Last updated: February 2026
Founder & Market Researcher
Taro has been actively investing in precious metals and financial markets for over 15 years. Frustrated by the lack of transparent, accurate gold pricing information in the UK, he built London Gold Exchange as a data-driven resource for fellow investors. The site combines real-time market data, verified dealer information from 242+ UK businesses, and insights drawn from years of hands-on experience in the gold market.
- ✓15+ years investing in precious metals & equities
- ✓Built verified database of 242+ UK gold dealers
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Disclaimer: Home testing methods provide indications but cannot guarantee gold authenticity with 100% certainty. For high-value items or definitive verification, seek professional XRF testing from an assay office or reputable dealer. The acid test involves corrosive chemicals - always use appropriate safety equipment. Information current as of February 2026.