Key Takeaways
Bright red is .999 fine silver and dark red is .925 sterling, not the other way around. Brighter always means more silver.
Green is ambiguous rather than negative. It points to roughly .500 silver, or to copper and brass, and needs a second test.
Plating is frequently high-purity silver, so surface tests read it as solid. File through to the base metal before you trust the result.
Acid gives you a band, not a number. Forged hallmarks, solder seams, and stone-set pieces all need XRF.
16 CFR §23.5 sets the sterling threshold at 925 parts per thousand. An .800 piece is real silver that still cannot be listed as sterling.
On a silver acid test, bright red means fine silver (.999), dark red means sterling (.925), brown means .800, and green means roughly .500. Most charts published online have the top two backwards. That single error is the difference between pricing a lot as sterling and pricing it as scrap, and what the metal is worth swings hard between the two.
This guide covers what each reaction color actually indicates, how to see if something is silver without ruining salable pieces, and the two situations where the acid test quietly gives you a wrong answer.
What Each Color on the Silver Acid Test Color Chart Means
Read the result within 30 to 60 seconds. The longer the solution sits, the darker it gets, which is how a genuine sterling reading drifts into looking like .800.
Green is the most misread result on the chart. It does not mean "not silver." It usually points to low-purity silver around .500, but copper and brass produce a similar green, and the two are hard to separate by eye. When you get green, the answer is another test, not a verdict.
The Two Colors That Get Inverted Most Often
Plenty of published versions of the silver acid test color chart list bright red as sterling and dark red as fine silver. It is backwards, and the chemistry explains why.
Silver testing solution is potassium dichromate in dilute nitric acid. The silver in the alloy produces a red reaction. The base metals produce brown and green ones. So the more silver in the piece, the cleaner and brighter the red. The more copper, the more that red muddies toward brown. Fine silver at 99.9% gives you the brightest reaction on the chart. Sterling, carrying 7.5% copper, reads a full shade darker.
Once you know the mechanism, you stop needing the chart. Brighter means more silver, every time. If you want to confirm the scale against a primary source, the solution manufacturer publishes it alongside the product.
Testing Incoming Inventory Without Damaging Stock
Never test on the face of a salable piece. Use a testing stone instead.
Rub the piece firmly on a testing stone to leave a visible metal streak.
Apply one drop of silver solution to the streak.
Watch the color develop and read it within 60 seconds.
Compare against the chart above, in consistent light.
Testing on a stone leaves the piece itself unmarked, which matters when you are spot-checking a lot you intend to sell. Test a stone streak from several pieces across the lot rather than one, since mixed lots are common in estate and closeout buys.
Use a solution formulated for silver. Gold solutions read silver inaccurately. Wear gloves, work with ventilation, and dispose of the solution per the manufacturer's directions. This is nitric acid, not a novelty kit.
Why Plated Pieces Can Still Read as Sterling
This is the failure mode that costs resellers the most money. Silver plating is often a layer of fine or near-fine silver over brass. A surface streak takes metal from the plating, not the base. The acid reads that plating exactly as it should: a bright red, high-purity result. The piece tests beautifully, and it is still plated.
The only reliable fix is to get underneath the layer. File a small notch in an inconspicuous spot — the inside of a shank, the back of a bail — until you reach the base metal, then streak from the notch. If the second reading comes back green, blue, or brown when the surface read red, you have plating over base metal. For the visual tells that flag plated stock before you reach for the acid, see our guide on separating plated from solid pieces.
Faster Checks to Run First
Acid is the confirmation step, not the opening move. Before the bottle comes out, three free checks cover most of how to detect silver and narrow the field fast.
Hallmarks
Look for 925, .925, STERLING, STER, or STG. International pieces may carry 800, 830, 835, or 900. An unmarked piece is not automatically fake (older and handmade work is often unstamped), but a mark gives you a claim to verify.
Magnet
Silver is not magnetic, and neither is the copper it is alloyed with. Neither one is attracted to a magnet at all, so a piece that shows any pull has ferrous metal in it. A better version of this test: slide a strong neodymium magnet down an angled silver surface. It should glide noticeably slowly, slowed by the eddy currents silver generates. A magnet that sticks, or one that drops like a stone, both point away from silver.
Ice
Silver has the highest thermal conductivity of any metal. An ice cube set on solid silver melts visibly faster than on a base-metal look-alike. It is a quick screen, not proof.
A note on two tests you will see recommended elsewhere: the rub test and the smell test. Tarnish on a cloth shows oxidation, which plated pieces also produce once the layer is thick enough, so black residue is weak evidence at best. Odor is not a usable signal at wholesale volume. Neither belongs in a buying decision.
Where Acid Testing Stops Being Enough
Acid gives you a purity band, not a number, and it cannot see past a few common problems. The chart teaches you how to see if silver is real; it does not teach you whether the stamp is honest.
Forged hallmarks: The acid tests the metal, not the honesty of the stamp.
Solder seams: Solder runs at lower purity than the body of a piece, so testing a joint understates the whole.
Mixed-metal and stone-set pieces: Acid and gemstones are a bad combination, and some settings cannot be filed safely.
Exact fineness: If you need a real number rather than a band, that is XRF analysis, which reads content without cutting into the piece.
For a high-value lot, an estate purchase, or anything where the difference between .800 and .925 changes the price materially, XRF at a bench jeweler is worth the fee. To learn how nickel-based look-alikes slip into wholesale channels in the first place, our breakdown of nickel silver against the real thing covers what to watch for.
What the FTC Requires Before You List It as Sterling
Verification is not only about margin. Once you resell, how you describe the metal is regulated.
Under the FTC's jewelry guides, it is deceptive to call a product "sterling silver," "sterling," "Ster.," or "solid silver" unless it is at least 925 parts per thousand pure. The unqualified word "silver" needs an accurate fineness figure directly in front of it. Under the National Stamping Act, sterling articles without solder carry a tolerance of four parts per thousand; with solder, ten.
The practical version for a retail buyer: a brown reading means the piece is genuinely silver and still cannot be listed as sterling. An .800 lot described as sterling in your storefront is a compliance problem regardless of whether you knew. Plated stock has to be disclosed as plated.
This is the real reason to test before the pieces reach your display case rather than after a customer questions them.
Stocking Silver You Don’t Have to Second-Guess
Testing every piece that comes through the door is a reasonable habit for estate buys and unfamiliar suppliers. It should not be necessary for your core inventory. Choosing suppliers who document purity up front is covered in our guide to buying wholesale.
Blake Brothers has worked as a wholesale jeweler in Milford since 1974, supplying retailers, boutiques, and resellers nationwide. Bill and Suan Blake hand-select inventory directly from artisan silversmiths in Thailand, Bali, and India, and every piece is guaranteed .925 purity. Our exclusive Mona Ann Designs line is produced in Thailand and hand-polished. Buyers who want to inspect stock in person are welcome at our showrooms in Milford, New Hampshire and Charlotte, North Carolina.
Browse the full wholesale catalog and order with free priority shipping on US orders $250+.
FAQs About Testing Sterling Silver
How can I tell if it's real silver before I pay for a lot?
Streak-test several pieces from across the lot on a testing stone rather than one representative piece. Mixed lots are normal in estate and closeout buys, and a single dark red reading tells you nothing about the other forty pieces.
How can I see if something is real silver without a test kit?
Check the hallmark, confirm no magnetic pull, and watch how fast an ice cube melts on it. Those three narrow the field at no cost, but none of them confirms purity. Acid or XRF does that.
What does bright red mean on a silver acid test?
Bright red indicates fine silver at .999 purity. Sterling silver reads a darker red because the 7.5% copper in the alloy mutes the reaction. If a chart tells you the reverse, it is wrong.
Does green mean the item is not silver?
No. Green usually indicates low-purity silver around .500, though copper and brass produce a similar color. A green result calls for a second test through a deeper cut, not a conclusion.
Can a silver-plated piece pass the acid test?
Yes, routinely. Plating is frequently high-purity silver, so a surface streak returns a bright red result. File a notch through to the base metal and test that streak instead.
How long should I wait before reading the result?
Between 30 and 60 seconds. The color continues darkening after that, which is how sterling readings end up misfiled as .800.
Can I test silver with gold testing solution?
Not accurately. Use a solution formulated for silver; gold solutions are calibrated for different reactions and will mislead you on purity.
