How to Tell If Old Jewelry Is Valuable

You open the old jewelry box and you're not sure what you're looking at. A tangle of chains, a few rings with stones you can't identify, brooches that might be from your grandmother's era or might be from a department store clearance rack circa 1985. Some pieces look substantial. Others look like they might be hollow. You have no idea if you're holding a hundred dollars' worth of scrap metal or something genuinely significant.

You're not alone in that uncertainty, and the good news is that you can learn quite a bit before ever setting foot in a jeweler's shop. A few minutes with a magnifying glass and a basic understanding of what stamps mean will take you further than most people realize. This guide walks you through the whole picture: metal marks, at-home tests, gemstones, period indicators, and when to stop guessing and call a professional.

Start With the Stamps

The single most useful thing you can do with an unfamiliar piece of jewelry is hunt for its stamps. Flip a ring upside down and look at the inside of the shank. Check the clasp on a necklace or bracelet. Inspect the back of a brooch near the pin stem. You may need a loupe or even a strong phone flashlight, but most stamped marks are there if you look.

What you find, or don't find, tells a lot right away, though it tells different things depending on where the piece was made.

If a piece comes from the United Kingdom or was made under British hallmarking law, the stamps you see were put there by an independent government-appointed assay office, not just the maker. The British hallmarking system is one of the oldest consumer-protection mechanisms in the world, dating back roughly 700 years. The word "hallmark" itself comes from London's Goldsmiths' Hall, where items were being officially marked as far back as 1478. The system was codified in the Hallmarking Act 1973 and requires three compulsory marks: a sponsor's or maker's mark, a metal-and-fineness mark, and an assay office mark. Four offices operate today, each with a distinct town mark: the Leopard's Head for London, an Anchor for Birmingham, a Rose for Sheffield, and a Castle for Edinburgh. When you see these on a piece, an independent authority verified the metal's purity before it left the assay office.

American pieces work on a fundamentally different principle. The United States has no government hallmarking system. Under the National Stamping Act of 1906, amended in 1961, the rule is not that manufacturers must stamp their jewelry. It is that if they do apply a quality or fineness mark, they must also stamp their registered trademark or full name alongside it, and the claim must be accurate. The FTC enforces the accuracy of those claims, but the initial decision to stamp or not stamp is voluntary. When you see "14K" or "925" on an American piece, you're reading the maker's own declaration, not a government-verified guarantee. That doesn't make it meaningless; most reputable manufacturers mark accurately. But it is a different kind of claim.

Gold Content: What the Stamps Really Mean

Gold jewelry stamps fall into two systems that express the same thing: how much of the metal is actually gold.

The karat system divides gold into 24 parts. A piece marked "14K" is 14 parts gold out of 24, or about 58.3% pure gold. An "18K" piece is 18 parts out of 24, or 75% gold. A "10K" piece, the legal minimum for gold in the United States, is about 41.7% gold. The millesimal fineness system, more common on European jewelry, expresses the same purity in parts per thousand: 585 equals 14K, 750 equals 18K, 417 equals 10K. Some pieces carry both notations; others carry only one. These numbers are exact and don't change. If a ring is stamped 750, it is 75% gold, full stop.

Where things get complicated is the difference between solid gold and gold-coated metal. Several stamp abbreviations exist specifically to describe pieces where only the surface layer is gold, and the distinction in value is dramatic.

Gold Filled pieces, stamped "GF" (often with a fraction and karat, like "1/20 14K GF"), are required by FTC regulations to have a gold alloy layer of at least 10 karat fineness that is mechanically bonded, not electroplated, to all significant surfaces. That layer must also constitute at least one-twentieth of the total metal weight of the piece. The 1/20 threshold is the key number. Gold Filled is the most durable of the coated options and was common in American jewelry from the late 1800s through mid-century, but it is not solid gold, and its resale value reflects that.

Gold Electroplate (stamped "GP" or "GE") is a completely different animal. FTC rules require a minimum gold thickness of just 0.175 microns, a fraction of the thickness of a human hair. Heavy Gold Electroplate ("HGE") steps that up to a minimum of 2.5 microns, but it is still a thin surface coating. Rolled Gold Plate ("RGP") falls between filled and electroplate: it requires a mechanical bond like gold-filled, but only needs to constitute one-fortieth of the total metal weight, half the gold-filled requirement.

Vermeil is a term you'll see on higher-end pieces. It has its own FTC definition and requires all three of the following: a base of sterling silver (not just any metal), a gold or gold alloy coating of at least 10 karat fineness, and a minimum gold thickness of 2.5 microns throughout. Using the word "vermeil" on a piece with a nickel or brass base is deceptive under FTC rules, regardless of how thick the gold layer is.

The practical takeaway: solid 10K, 14K, or 18K gold has intrinsic melt value that scales with the metal's weight and current spot price. A gold-plated piece with 0.175 microns of gold on a brass base has essentially no scrap metal value, regardless of how nice it looks.

Silver and Platinum

Silver pieces follow a similar stamp logic. In the United States and most of the English-speaking world, "Sterling," "Ster.," or "925" indicates the piece is at least 92.5% pure silver, the international sterling standard. "Coin" or "Coin Silver" indicates at least 90% silver content, a standard common in American silverwork from the early and mid-1800s before sterling became dominant. Some European and older continental silver is marked 800, indicating 80% purity. Real silver, but less pure than sterling.

The letters EPNS, which you'll see on a lot of Victorian and Edwardian serving pieces and some jewelry, stand for Electroplated Nickel Silver. Despite the name, EPNS contains no silver at all. The "silver" in the name refers to the silver-colored appearance of nickel silver, which is an alloy of copper, zinc, and nickel. EPNS pieces can be beautiful and collectible as decorative objects, but they have no precious metal value.

Platinum pieces are typically marked with some combination of "PLAT," "PT," or "PLATINUM" alongside a fineness number. 950 is the most common, indicating 95% pure platinum. Platinum commands a premium and is denser and heavier than gold, so a small platinum piece can be surprisingly heavy. If you're uncertain whether an unmarked white metal piece is platinum, white gold, or silver, you need a professional test.

At-Home Tests: What Actually Works

A few simple tests can help narrow things down, but it's worth being clear about what they can and cannot do.

The magnet test is genuinely useful as a screening tool. Genuine gold, silver, and platinum are not magnetic. If a piece pulls hard toward a strong rare-earth magnet, you're likely looking at a plated piece over a ferrous base, or costume jewelry. But passing the magnet test doesn't prove a piece is solid gold. Plenty of non-magnetic metals (brass, copper, nickel, aluminum) are not magnetic either. The magnet test rules things out; it doesn't rule them in.

Acid test kits are sold at jewelry supply stores and online, and they do work, but they come with real downsides worth understanding. Using one requires physically scratching or rubbing the piece against an abrasive test stone to remove some metal, then applying a corrosive acid to the scratch mark. You are, in that process, actually removing gold from the piece and damaging its surface. The acids involved are corrosive and require careful handling and storage. There is also a specific problem with plated pieces: to determine whether a piece is plated rather than solid, you need to scratch deep enough to get through the surface coating to the base metal beneath. That is not a light test. For pieces you care about aesthetically, an acid test is a last resort, not a first step.

Electronic gold testers exist and are used by dealers, but they have limitations, especially at the consumer level. At-home thermal conductivity testers marketed as diamond testers have a significant blind spot that we'll cover in the gemstone section below.

Discard the folk tests you may have read about: the breath-fog test, the ice test, dropping a piece in water to check whether it floats. These are not reliable methods for identifying precious metals or genuine stones. They circulate online because they sound clever, but they don't hold up to scrutiny.

Gemstones: Why You Almost Certainly Can't Value Them at Home

If the metal stamps are the first place you look, the stones are where most people feel stuck. Gemstone identification is genuinely difficult, and the landscape has changed dramatically in the last few decades.

The most important distinction to understand is between a simulant and a synthetic (or lab-grown) gemstone. These are completely different things and are often confused.

A simulant, sometimes called an imitation stone, is a material that looks similar to a target gem but has different chemical composition, crystal structure, and optical properties. Cubic zirconia (CZ) is the most common diamond simulant, introduced commercially in the late 1970s. It's colorless, highly refractive, and ranks 8.5 on the Mohs hardness scale. It has slightly more fire than diamond but less brilliance, and it yellows with age. Glass is another simulant, with a much lower refractive index that trained eyes and instruments can detect. White sapphire and white topaz are natural minerals sometimes used as simulants. None of these are diamonds, and none share a diamond's chemical or physical properties.

A lab-grown or synthetic diamond is an entirely different matter. Lab-created diamonds have the same chemical composition, crystal structure, and optical properties as natural mined diamonds. They are, by every physical measure, real diamonds. This is what makes them so difficult to identify at home: lab-grown diamonds pass every consumer test, including thermal conductivity testers marketed as diamond detectors. The only practical way to distinguish a lab-grown diamond from a natural one is sophisticated laboratory analysis.

There is also a notable trap that catches even careful buyers. Moissanite, a silicon carbide mineral first found in meteorite fragments and now produced synthetically, is harder than CZ (approximately 9.25 on the Mohs scale) and has optical properties closer to diamond than CZ does. In fact, moissanite produces more than twice the fire of diamond, which in larger stones can create a sparkle that experienced eyes recognize as not quite right for diamond. But here is the specific problem: standard handheld thermal conductivity testers read moissanite as "Diamond." The thermal properties of moissanite are close enough to diamond that these common testers cannot distinguish between them. Separating moissanite from diamond requires an electrical conductivity tester or gemologist-grade equipment. The simple handheld units that correctly flag cubic zirconia will not flag moissanite.

The bottom line on gemstones: at-home tests can help you identify obvious simulants in some cases, but no consumer test definitively proves a stone is a natural diamond, ruby, sapphire, or any other specific natural gem. For any piece where the stone's identity and quality materially affect its value, you need a gemologist.

Designer Signatures and Signed Pieces

One factor that can multiply a piece's value far beyond its metal and stone content is the maker's signature or brand mark. A plain gold ring with a small diamond and one marked with a Tiffany & Co. or Cartier signature are not remotely comparable in value, even if the metal weight and stone quality are identical. The brand premium is real and substantial.

This extends to signed costume jewelry, which is its own distinct collecting category. Pieces signed by makers like Miriam Haskell, Trifari, or Eisenberg, which may have little or no precious metal content, can be legitimately collectible and valuable to the right buyer. Age, rarity, and condition all factor in, but the signature is what triggers the collectibility.

The complication is that counterfeiting exists. Fake Tiffany, fake Cartier, and fake examples of desirable costume jewelry brands are in circulation. If you believe you have a signed piece from a significant maker, authentication by someone who knows that specific maker's work is essential before you put a number on it or sell it.

What Else Drives Value Beyond the Metal

Period and age are meaningful but require some context to interpret correctly. The jewelry trade uses approximate date ranges to categorize historical styles: Georgian pieces date roughly to 1714-1837; Victorian spans approximately 1837-1901; Edwardian runs roughly 1901-1915. Art Nouveau overlaps that, running approximately 1890-1910; Art Deco roughly 1920-1935; Retro (also called Hollywood Regency) approximately 1935-1950; mid-century modern from around the 1950s into the 1960s. These are industry conventions with fuzzy edges, not rigid definitions, but they're useful for communicating style period and approximate age.

Age alone doesn't guarantee value. Condition matters enormously. A pristine Georgian brooch and a damaged one are in completely different value categories. Rarity matters, as does the specific market for a given style or maker at a given time. Spot prices for gold and silver change daily and directly affect the baseline scrap or melt value of any piece with precious metal content.

Appraisal vs. Evaluation: Know the Difference

A casual verbal look from a jeweler and a formal written appraisal are not the same thing. Knowing which you need, and for what purpose, will save you confusion and money.

A grading report assesses quality characteristics, such as the cut, color, and clarity of a stone, or the fineness of the metal, but does not include a dollar value opinion. A formal jewelry appraisal is a written document that describes the item, assesses its quality, and provides a specific opinion of value for a stated purpose.

That stated purpose matters more than most people expect, because there are at least three different value types that an appraiser might assign to the same piece, and they will produce meaningfully different numbers.

Insurance or replacement value is the highest of the three. It represents the realistic cost to replace the item with a comparable one at a retail jewelry store. Insurance appraisals are intentionally higher than what you could sell the piece for, because they reflect retail replacement cost.

Fair market value reflects what a willing buyer would actually pay a willing seller for the item in its current condition, with neither party under pressure. This is the number the IRS uses for estates, gifts, and charitable donations, and it is typically substantially lower than an insurance appraisal.

Liquidation value is lower still. It reflects forced-sale or distressed-sale situations, where the seller needs to move the piece quickly.

When you get an appraisal, clarify which type is being provided, because the number alone without context can be significantly misleading. And if you are thinking about selling a piece, get an appraisal from someone who is not also trying to buy it. An independent appraiser has no stake in the valuation; a buyer offering to appraise your piece as part of a purchase conversation does.

For credentials, look for an appraiser who holds at minimum a GIA Graduate Gemologist (G.G.) diploma and who belongs to a recognized professional appraisal organization such as the National Association of Jewelry Appraisers (NAJA) or the American Society of Appraisers (ASA).

Selling: Protect Yourself First

If you decide you want to sell, understand the baseline before you walk in anywhere. Melt or scrap value is calculated from the piece's weight, its metal purity, and the current spot price for that metal, minus the refiner's margin. It represents the absolute floor: what the metal is worth melted down and refined. A significant piece's actual value may be far above melt, particularly if it's signed, period-correct, or has quality stones. Knowing the melt value gives you a reference point for offers you receive.

Get more than one offer before you accept anything. Prices vary between buyers, sometimes substantially. Be cautious of pop-up buying events and mail-in gold services, which make it difficult to comparison shop or reclaim a piece you decide not to sell. For anything you believe may be genuinely significant, whether signed, antique, or set with potentially valuable stones, get an independent written appraisal before entertaining any offers. You cannot effectively evaluate an offer if you don't know what you have.

When You're Ready for a Professional Opinion

Understanding what your jewelry might be takes you far. Knowing what it actually is, with confidence, takes a professional.

At Millard Jewelry & Coin in Omaha, we offer free evaluations on estate jewelry and coins. Bring in what you have, and we'll take a real look: read the stamps, assess the metal, and tell you honestly what we see. No pressure, no obligation. If what you have warrants a formal written appraisal for insurance, estate, or selling purposes, we can arrange that too. The goal is simply to give you accurate information so you can make whatever decision is right for you.