How to Test Gold at Home | Safe DIY Methods

You can check gold at home with stamps, magnet, density, streak, and acid touchstone methods while keeping damage risk low.

Got a chain from a drawer, a coin from a relative, or a ring from a market stall? You can screen it at home before paying for a pro appraisal. This guide walks you through fast checks first, then gives you step-by-step methods that provide stronger proof. You’ll see what each test can and can’t tell you, what tools you need, and how to avoid harming a plated item.

What You Can Learn From At-Home Tests

No single check tells the whole story. A quick pass with a magnet weeds out base-metal fakes. A clean stamp strengthens the case. Density and touchstone tests go further. Stack a few methods and you’ll reach a solid yes or no for most household finds.

Common Tests And What They Show

Start with low-risk checks, then move to stronger confirmation. Here’s a compact map of the methods you’ll use.

Test	What It Indicates	What You Need
Stamp/Hallmark Check	Karat mark and maker/assay info that point to real gold	Bright light, 10× loupe, stamp list
Magnet Check	Screen for iron or steel; real gold isn’t magnetic	Strong neodymium magnet
Weight And Size Clues	Gold feels dense for its size; fakes feel light	Digital scale, ruler/calipers
Density (Water Displacement)	Specific gravity near 19.3 suggests high purity	Kitchen scale (0.01 g), water, cup, thread
Ceramic Streak	Gold-colored streak hints at real alloy; gray/black suggests base metal	Unglazed ceramic tile
Touchstone + Acids	Compares streak to known karats; stronger confirmation	Touchstone, acid kit, reference samples, PPE
Electronic Tester	Conductivity/resistance profile for a karat estimate	Benchtop or pen-style tester

Safety And Damage Risk

Wear gloves and eye protection when you use acids. Work with good airflow. Keep acids far from kids and pets. For plated items, avoid deep filing or harsh rubbing on visible faces. Test in a spot that doesn’t show, like the back of a clasp or inside a ring.

Step 1: Read Stamps And Hallmarks

Use a loupe and bright light. Look for karat marks such as 24K, 22K, 18K, 14K, 10K, or fineness marks like 999, 916, 750, 585, 417. You may also see a maker’s mark and, in some regions, an assay office mark. A clean set of marks doesn’t prove purity on its own, but it’s a strong start. To understand what lawful marks mean in trade rules, see 16 CFR Part 23 for how karat claims are used in commerce. Some countries also require a formal assay office stamp on precious metal goods.

Common Red Flags On Stamps

“GP,” “HGE,” “GEP,” “RGP,” “G.F.” These point to plated or gold-filled items.
Misspelled hallmarks, uneven fonts, or stamps placed where wear would vanish them too fast.
Only a brand name with no purity mark on a piece that should carry one.

Step 2: Use A Magnet

Gold doesn’t stick to a magnet. Hold a strong neodymium magnet near the piece. If it jumps, it isn’t solid gold. If it slides only a touch, you may be seeing the effect of steel parts in a clasp or spring. Many plated fakes use magnetic cores, so this quick pass saves time.

Step 3: Check Weight And Size

Gold packs mass. A thick ring or a coin will feel heavy for its size. Weigh the item and compare to a known piece of similar volume. Thin, bulky pieces that feel light lean away from real gold. This step is a clue, not a verdict, since dense base alloys exist.

Step 4: Run A Density Test At The Sink

This method uses water displacement to estimate specific gravity. It’s simple, cheap, and far more telling than a guess by feel.

What You’ll Need

Digital scale that reads to 0.01 g
Measuring cup or beaker filled with room-temperature water
Thin thread or dental floss
Pencil and paper for the math

Steps

Weigh the dry item. Write down dry mass m_dry.
Tie thread to the item. Tare the scale with the cup of water on it.
Lower the item fully into water without touching the cup. Note the apparent mass increase. That number is the water displaced, which equals the item’s volume in grams (since water is 1 g/mL).
Compute density: density = m_dry / volume.

Reading The Result

Near 19.3 g/cm³: points to high-purity gold or a dense noble-metal alloy.
Between ~14 and 18 g/cm³: common for 10K–18K alloys due to mixed metals.
Well below 12 g/cm³: likely not gold.

Dry and warm the item after the test to prevent water marks on finishes.

Step 5: Try A Ceramic Streak

Rub a corner of the piece on an unglazed ceramic tile. A rich, gold-colored streak is a good sign. A gray or black streak points to base metal. This is a screening step, not a karat readout, and it can leave a tiny rub mark. Pick a hidden spot.

Step 6: Confirm With Touchstone And Acids

A touchstone kit gives you a stronger answer and a karat estimate. It compares the streak from your item against reference alloys while you place tiny acid drops on the stone. Pros use this every day because it’s fast and low damage when done right. For a clear walk-through on solution strengths and setup, see the GIA touchstone method.

How To Run The Touchstone Test

Clean a small area of the item with mild soap and water; dry it.
Make a firm streak on the stone.
Make reference streaks from known karat needles or verified pieces.
Place the acid drop sized for the karat you’re checking. Watch which streaks fade or hold.
Bracket the result. If a 14K streak holds and a 18K streak fades, your item aligns near 14K–16K.

Tips To Keep Damage Low

Streak the item on an unseen edge.
Neutralize acids with baking soda and water on the stone, not on the jewelry.
Skip deep filing. A tiny rub is enough.

Step 7: Use An Electronic Tester (Optional)

Electronic testers read conductivity or resistivity. Pen-style units are handy for a pass/fail screen. Benchtop units can estimate karat across white, yellow, and rose alloys. Calibrate before use and test bare metal, not lacquered or dirty surfaces.

Close Variant Heading: Home Gold Testing Rules And Limits

Consumer rules and trade guides shape what you can rely on when you read marks. In the U.S., karat words and fineness stamps follow specific definitions in trade guidance. Some regions also use legally controlled hallmarks from assay offices. Stamps are strong signals when paired with test results, yet counterfeits exist, so always stack methods.

White, Yellow, And Rose Alloys Behave Differently

White alloys often include nickel, palladium, or other whitening metals. They can look silvery next to a yellow item of the same karat. Rose alloys carry copper that nudges density down a touch and adds a reddish hue. These shifts don’t change the basic rules above; they just affect the exact density and acid response by a small margin.

Gold-Plated, Gold-Filled, And Solid: Tell Them Apart

Plated items carry a thin layer of gold over base metal. Scratches or worn edges may show color changes. “G.F.” or “1/20 14K” marks point to gold-filled, which bonds thicker gold to a core but still isn’t solid. Touchstone testing reads the surface only. If you suspect plating, test in a spot where wear has exposed the core or make a tiny notch in a hidden area and streak the base.

Coins And Bullion: Extra Clues

Many coins have well-known mass and size. Compare your coin’s weight and diameter to published specs. Any mismatch signals trouble. Bullion bars often include serial numbers and known makers. Suspect bars deserve a step-by-step density check and a touchstone pass on an edge.

When To Call A Professional

If you’re about to sell a high-value piece, or if your tests conflict, book a jeweler or assay office. They can run XRF, sample assays, or laser testing that reads deeper than surface. That level of proof matters for resale and insurance.

Interpreting Results: What Patterns Mean

Use the table below to translate test combos into likely outcomes. No single method stands alone. Patterns tell the story.

Test Pattern	Likely Outcome	Next Step
Non-magnetic, hallmark present, density near target	Strong case for real gold of the stamped range	Touchstone to bracket karat
Magnetic core, gold-colored plating	Base metal under thin gold	Skip acid on face; test a hidden spot
No stamp, non-magnetic, density mid-range	Could be lower-karat alloy	Touchstone and compare to 10K/14K
Stamp says high karat, but density low	Suspicious or hollow build	Weigh against size; test more points
Touchstone matches 14K, electronic reads similar	Consistent result	Proceed with confidence
Touchstone mixed, streak fades across ranges	Plated or odd alloy blend	Pro evaluation

Hands-On Walkthrough: Full At-Home Workflow

Here’s a simple order that balances safety and certainty:

Clean the piece with mild soap and warm water; dry with a soft cloth.
Scan for stamps with a loupe. Note any karat or fineness marks and maker marks.
Run the magnet check near the clasp and the body.
Weigh the item and log the number.
Do the density test. Keep notes.
Make a tiny streak on ceramic. Note the streak color.
Use a touchstone kit to bracket karat. Compare to known references. Follow solution safety steps as shown in the GIA method linked above.
If needed, confirm with an electronic tester.
Save your readings and photos. They help if you sell or insure the item.

Myths And Mistakes To Avoid

Biting: Teeth marks don’t prove anything and can damage a coin.
Vinegar bath: Can stain finishes and doesn’t give a clear karat read.
Single-test verdicts: One pass can mislead. Stack methods.
Testing on a polished face: Always pick a hidden spot for any rub.

What Karat Numbers Mean

Karat describes the gold fraction in 24 parts. A 14K ring carries 14 parts gold and 10 parts other metals. Trade rules and guides standardize the words and numbers used in stamps, which helps buyers judge claims. When you see 585 on a band, that’s the same as 14K by fineness math. This shared language across shops and borders makes your stamp check far more useful.

Quick Reference: Karats, Fineness, And Typical Marks

Use this table while you read stamps during your first pass.

Marking	Gold Content	Common Stamp
24K	~99.9%	999 or 24K
22K	~91.6%	916 or 22K
18K	75.0%	750 or 18K
14K	58.5%	585 or 14K
10K	41.7%	417 or 10K

When A Stamp Isn’t Enough

Stamps can be forged, and genuine vintage pieces may lack modern marks. That’s why the rest of the tests matter. If money is at stake, finish with a trusted jeweler or an assay office. Trade bodies and assay labs can back claims with formal reports.

Keep Your Tools Handy

A small home kit pays off. A loupe, magnet, ceramic tile, a scale, a measuring cup, and an acid touchstone set cover most needs. Store acids in their original bottles, sealed and upright. Replace them when they lose strength.

What To Do After You Confirm

If you plan to sell, gather your notes, stamp photos, and test results. Clean the piece gently before a shop visit. Ask about the testing method they’ll use in-store. If offers vary a lot, get a second opinion.

Final Checklist You Can Save

Stamp present and looks right
Magnet screen passed
Weight and size feel dense
Density test near target
Streak looks right on ceramic
Touchstone bracketing matches a karat range
Electronic tester aligns (if used)

Useful references while you test at home: Trade guidance on karat claims is laid out in the U.S. at 16 CFR Part 23, and practical lab steps for touchstone acids are described in the GIA touchstone method.