Platinum Purity Basics for Sellers: Read Your Stamp Value

Understanding platinum purity basics for sellers is the single fastest way to know what your piece is worth before you walk into a buyer’s office or ship it off. Purity determines how much actual platinum is in the item, and that directly controls the melt value. Whether you have a ring, a bar, or a loose piece of scrap, the purity stamp is where every honest price calculation starts.

Platinum is not a one-size-fits-all metal. Most pieces are alloys – blends of platinum with small amounts of other metals like iridium, cobalt, or ruthenium added for strength. The percentage of pure platinum in that blend is the fineness, and it is usually stamped right on the piece. Knowing how to read that stamp, what it means for price, and how buyers verify it will help you sell with confidence rather than guesswork.

What Platinum Purity Actually Means

Purity, or fineness, is the proportion of pure platinum in an item expressed as parts per thousand. A piece stamped PT950 is 950 parts platinum out of 1,000 – in other words, 95% pure. The remaining 5% is other metals added to make the alloy workable.

The U.S. Federal Trade Commission sets the floor: a piece must contain at least 500 parts per thousand of platinum to be sold as “platinum” without further qualification. Items at 950 parts per thousand or above can carry a simple stamp – PLAT, Pt, PT950 – with no extra language required. That rule exists to protect buyers, but sellers benefit from knowing it too, because it means not every “platinum” item carries the same metal content.

The Common Purity Marks and What They Tell You

For most sellers, PT950 is the number that matters most. It is the benchmark for high-end platinum jewelry and the most common fineness you will encounter. PT999.5 is the standard for investment bullion – bars and coins built to trade directly against the metal market.

Lower purities like PT900 and PT850 are still genuine platinum. They just contain less of it, which means a lower melt value per ounce of item weight. That is a straightforward trade-off, not a defect.

How Purity Affects the Price You Get

The math is simple. Buyers pay for the pure platinum content in your piece, not the total weight. The formula is:

Spot price x purity fraction x item weight = gross metal value

At the time of writing, platinum spot is about $1,904 per troy ounce. Run the numbers on common purity levels:

Live Platinum Spot Price – Accurate Precious Metals Refineries

The difference between PT950 and PT900 works out to roughly $95 per troy ounce of item weight at current spot prices. On a heavy piece – say a 10-gram ring – that gap is meaningful. On a thin band, less so. Either way, knowing the purity before you get an offer means you can check whether the math adds up.

Platinum Purity Basics for Sellers: Reading the Hallmark

The hallmark is the fastest clue you have. Look for a stamp on the inside of a ring shank, the clasp of a necklace, the surface of a bar, or the edge of a coin. Common stamps include:

• PT950 or 950Pt – the most common jewelry mark
• PT900 or 900Pt – older pieces, especially Japanese and European jewelry
• PT999 or PT999.5 – bullion-grade material
• PLAT or Pt – a general platinum stamp, usually found on pieces at 950 or higher
• 850Pt – lower-purity pieces, less common in the U.S.

A worn or missing stamp does not mean the piece is not platinum. It means you cannot rely on visual identification alone. That matters because platinum, white gold, and sterling silver can look nearly identical to the naked eye. Density is one rough clue – platinum feels noticeably heavy for its size – but that is not a substitute for proper testing.

Platinum vs. White Gold vs. Silver: Why It Matters for Sellers

Confusing these three metals is one of the most common seller mistakes. They can look identical in a photograph and nearly identical in person, but their values are completely different.

White gold is typically 14k or 18k gold alloyed with white metals like palladium or nickel. At current spot prices, gold sits at about $4,544 per ounce at the time of writing – more than double platinum’s spot price. But white gold at 14k is only 58.5% pure gold, so the actual metal content per ounce of item weight is lower than it first appears.

Silver is in a different league entirely. Sterling silver is 92.5% pure, but silver spot is around $76 per ounce at the time of writing. A silver piece that looks like platinum is worth a fraction of what a platinum piece of the same weight would fetch.

Palladium adds another layer of complexity. It is a platinum-group metal that looks similar to platinum and currently trades at about $1,357 per ounce at the time of writing. Some older white metal jewelry is palladium, not platinum, and the two require testing to distinguish.

The point for sellers: do not assume. Get the metal identified before you accept an offer. A platinum jewelry selling guide can help you understand what questions to ask and what documentation to bring.

Bullion, Jewelry, and Scrap: Three Different Selling Situations

Not all platinum sells the same way, and understanding the category your piece falls into changes your expectations.

Bullion

Platinum bullion – bars and coins – is the most straightforward to price. The purity and weight are standardized, so the calculation is direct. A 1 oz Platinum Bar – Argor-Heraeus (Carded) or a 1 oz Platinum Kangaroo Coin 2026 both carry a known fineness, making offers easy to compare across buyers. Bullion typically trades closest to spot because there is little ambiguity about what you have.

Jewelry

Jewelry pricing is less predictable. A PT950 ring from a recognized designer or luxury brand may command more than melt value if there is a secondary retail market for it. An unbranded or damaged piece usually sells for its metal content. Condition, weight, and whether stones need to be removed all affect the final number. Check out platinum coins guidance for context on how purity plays into different item types.

Scrap

Scrap is the most variable category. It includes broken jewelry, industrial remnants, dental scrap, and mixed-metal items. Solder joints, stone settings, and mixed alloys can all affect the recoverable platinum content, which is why accurate testing is especially important here. Offers on scrap are typically based on the assessed metal content after testing, not on face appearance. If you have platinum scrap, a platinum scrap buyer who uses XRF testing will give you the most reliable number.

How Buyers Verify Platinum Purity

Reputable buyers do not guess. The standard method for non-destructive purity testing is XRF analysis – X-ray fluorescence. The device fires X-rays at the metal surface and reads back the elemental composition in seconds. It is fast, accurate, and does not damage the piece.

Some buyers also use acid testing for a quick initial screen, though XRF is more precise. Fire assay – melting a sample and chemically separating the metals – is the most accurate method but is destructive and typically used for larger lots of scrap or industrial material.

When you bring a piece to Accurate Precious Metals, it is assessed for purity using reliable testing methods. The offer reflects the actual metal content, not an assumption based on appearance or the stamp alone. That matters when you are talking about a metal that can be worth nearly $1,900 an ounce at current spot prices.

Common Misconceptions Sellers Should Drop

Sellers walk in with assumptions that cost them time and sometimes money. Here are the ones worth correcting before you go:

• “Platinum is always pure.” Most platinum items are alloys. PT950 – 95% pure – is the standard for fine jewelry, not 100%.
• “White metal means platinum.” White gold, silver, and palladium all look similar. Testing is the only way to know.
• “A stamp is proof of purity.” Stamps are useful, but they need to be backed up by testing before any serious transaction.
• “Platinum is always worth more than gold.” Not at current prices. Gold spot sits at about $4,544/oz at the time of writing, more than double platinum’s $1,904/oz. The metals trade independently.
• “Higher purity always means a better deal.” It means more pure platinum per ounce of item weight, but the final price also depends on weight, condition, form (bullion vs. jewelry vs. scrap), and market conditions.

Practical Steps Before You Sell

Selling Platinum with Accurate Precious Metals

Accurate Precious Metals has been buying and selling precious metals for over 12 years from its Salem, Oregon location. With more than 1,000 five-star customer reviews and competitive pricing updated to reflect live spot prices, it is one of the most trusted options for sellers across the country.

When you sell my platinum, you are working with a specialized precious metals dealer – not a pawn shop. The difference matters. A pawn shop generalizes. Accurate Precious Metals focuses on precious metals, which means the team understands purity grades, hallmarks, and market pricing in a way that translates directly to a fair, competitive offer.

For sellers in the Salem area, in-person service is available at the physical location. You can bring your platinum jewelry, bars, coins, or scrap directly and have it assessed on the spot. If you are anywhere else in the United States, the mail-in service makes the process straightforward: request a free insured shipping kit, send your items, and receive a competitive offer based on current spot prices. Fast payment follows once you accept.

Whether your piece is a high-purity bullion bar, a PT950 engagement ring, or a bag of scrap from an industrial setting, Accurate Precious Metals handles it. The process is the same: assess the purity, weigh the metal, and make an offer based on what is actually there. You can also check current platinum spot prices on the site before you come in or ship anything, so you have a baseline before the conversation starts.

If you want to understand more about how purity interacts with pricing across different platinum forms, the platinum purity and pricing context page covers that in detail.

Local or remote, the process is designed to be straightforward. Call (503) 400-5608 with questions, or visit AccuratePMR.com to start the mail-in process.

Frequently Asked Questions

Sources

1. Chula Vista Coins – Platinum Purity and Hallmark Reference
2. Jewelove – Platinum Jewelry Purity Standards
3. Goldfolio – Identifying Platinum and White Metal Alloys
4. The Natural Sapphire Company – FTC Platinum Labeling Rules
5. Gemmyo – Platinum Alloy Composition and Jewelry Standards
6. Austin Diamond Buyer – Precious Metal Testing Methods