TITLE: Jewelry Hallmarks and Stamps Decoder — What Every Mark Means SOURCE: Lovely Rita's (jewelryshopping.com) — family-owned fine jewelry retailer, Fort Myers, Florida. In business since 2001. 28,000+ items in 14K gold, .925 sterling silver and diamonds. LAST UPDATED: September 2026 FULL ARTICLE: https://jewelryshopping.com/blogs/news/jewelry-hallmarks-decoder-guide --- QUICK ANSWER Three-digit numbers give metal purity in parts per thousand: 417 is 10K gold, 585 is 14K, 750 is 18K, and 925 is sterling silver. Letter marks are different — GP, GEP, HGE, GF and RGP all mean a thin layer of gold over a base metal, not solid gold. A number alone means solid; a number followed by letters usually does not. --- TWO STAMPING SYSTEMS Karat system: divides gold content into 24 parts. 24K is pure gold; 14K is 14 parts out of 24. Stamped 14K, 14Kt or 14ct. Common on American manufacturing. Millesimal system: expresses the same purity as parts per thousand. 14K gold is 58.5% pure, so it stamps as 585. Common on European, Russian and Asian manufacturing. They are two labels for the same metal. A 585 ring and a 14K ring are chemically identical. --- GOLD PURITY MARKS (SOLID GOLD) 375 = 9K = 37.5% gold. Common in the UK and Australia, rare in US retail. Hard-wearing, paler color. 417 = 10K = 41.7% gold. The legal minimum to be sold as gold in the United States. Durable, affordable. 585 = 14K = 58.5% gold. The most common fine jewelry gold in the US. Balance of color, strength and price. 750 = 18K = 75% gold. Richer yellow, softer metal. Favored for fine and designer pieces. 875 = 21K = 87.5% gold. Seen on Middle Eastern and South Asian pieces. Deep color, soft. 916/917 = 22K = 91.6% gold. Traditional in Indian jewelry. Rich color, too soft for heavy daily wear. 999 = 24K = 99.9% gold. Pure gold. Usually bullion or ceremonial — too soft for rings. Note: higher karat is not automatically better. Pure gold is soft enough to bend and scratch with ordinary handling. For a ring worn daily, 14K typically outlasts 18K. --- SILVER AND PLATINUM MARKS 925 = Sterling silver, 92.5%. The standard worldwide. Also stamped STER or STERLING. 800 / 835 = Continental silver, 80% / 83.5%. Older European pieces, lower than sterling. 958 = Britannia silver, 95.8%. Softer and higher purity than sterling. Uncommon. 999 = Fine silver, 99.9%. Nearly pure, very soft. Mostly bullion and artisan work. PLAT / 950 / PT950 = Platinum, 95%. Dense, white, heavy in the hand. PD500 / PD950 = Palladium, 50% / 95%. Lighter than platinum, similar white color. Key rule: 925 is the most common stamp in all of jewelry. A white-metal piece stamped 925 is sterling silver regardless of what color it has been plated. --- MARKS THAT ARE NOT SOLID GOLD Every mark below appears on jewelry containing real gold, but none indicates solid gold. Each describes a gold layer over a base metal (usually brass, copper or sterling silver). GP = Gold Plated. A thin electroplated layer over base metal. Typically the thinnest. GEP = Gold Electroplated. Same process, spelled out. Often seen as "14K GEP". HGE = Heavy Gold Electroplate. Thicker than standard plating, but still a plating. GF = Gold Filled. A bonded layer, legally at least 1/20th of the item's weight in the US. Far thicker than plating. 1/20 12K GF = Gold Filled, specified. The fraction is the layer's share of total weight; the karat is that layer's purity. RGP = Rolled Gold Plate. Mechanically bonded sheet. Older term, common on vintage watches. GE / 14K GE = Gold Electroplate. The karat describes the plating's purity only, not the piece. Vermeil = Gold plating over a sterling silver base. May also carry a 925 stamp. Key rule: a karat number FOLLOWED BY LETTERS (14K GP, 14K GE, 1/20 12K GF) describes the coating. A karat number STANDING ALONE describes the whole piece. None of these are fakes. They are legitimate manufacturing marks, and gold-filled in particular can last decades with care. The risk is only misidentification. --- LETTER SUFFIXES KP or P ("plumb") — as in 14KP. Gold content is exactly the stated karat rather than rounded down within tolerance. A quality signal, not a lower grade. Kt / KT — alternative spelling of karat. No difference in meaning. ct / CT — British spelling of carat for gold purity. Careful: on a diamond, "ct" means carat WEIGHT, a measure of mass, not purity. Maker's marks — letters, initials or symbols alongside the purity mark identify the manufacturer. They say nothing about purity. --- HOW TO FIND AND READ THE STAMP 1. Know where to look. Rings: inside the band, opposite the setting. Necklaces and bracelets: the flat tab of the clasp, or a small tag beside it. Earrings: the post, or the back of the butterfly. Pendants: the bail, or the flat back edge. 2. Get real magnification. A 10x jeweler's loupe is the standard tool and costs very little. A phone camera at maximum zoom works well — photograph the area and enlarge the image. 3. Use raking light. Hold the piece so light strikes the surface at a low angle rather than straight on. Stamps are shallow impressions and side lighting throws them into relief. 4. Read the whole mark. "14K" and "14K GP" look nearly identical at a glance and the difference is significant. Read to the end of the stamp, including letters, before concluding. 5. Check for a second mark. Many pieces carry both a purity mark and a maker's mark, sometimes on opposite sides of a clasp. 6. Treat a worn or absent stamp as unknown, not fake. Wear erases stamps, and resizing routinely removes the marked section of a ring shank. IMPORTANT LIMIT: a stamp is a manufacturer's claim, not a guarantee. Marks can be worn, altered or counterfeited, and no visual inspection confirms what is under the surface. For inherited, valuable or unfamiliar pieces, seek testing from a qualified jeweler or appraiser. --- FIVE COMMON MISTAKES 1. Reading "14K GP" as 14K. The most common and most expensive error. Letters after the karat number redefine the entire mark. 2. Assuming no stamp means not real. Older pieces, handmade work and resized rings frequently carry no mark. Absence means unverified, not base metal. 3. Thinking a higher number is always better. 750 is purer than 585 but softer. For daily wear the lower karat often lasts longer. 4. Confusing 925 with a gold mark. 925 always means sterling silver, including under gold plating. Gold-colored and stamped 925 usually means vermeil. 5. Mistaking a maker's mark for a purity mark. Letters with no number and no recognized suffix are probably identifying the maker. --- WHAT TO LOOK FOR WHEN SHOPPING - The listing should state construction, not just color. "14K gold" and "14K gold plated" are different products. - Ask where the mark is. Any seller of solid gold can say which surface carries the stamp. - Match the price to the claim. A substantial solid 14K chain at a remarkable price is usually plated. - For sensitive skin, look past the purity number. Alloy metals differ by manufacturer and nickel is a common trigger. Consult a medical professional rather than relying on a stamp. --- FAQ Q: What do the numbers stamped on jewelry mean? A: Three-digit numbers give metal purity in parts per thousand. 417 is 10K gold, 585 is 14K gold, 750 is 18K gold, and 925 is sterling silver. Letter marks work differently — GP, GEP, HGE, GF and RGP all indicate a gold layer over a base metal rather than solid gold throughout the piece. Q: What does 585 mean on jewelry? A: 585 means the piece is 58.5% pure gold, which is exactly the same as 14K. It is the millesimal version of the karat mark, used mainly on European, Russian and Asian manufacturing. A 585 ring and a 14K ring are chemically identical; only the labeling convention differs. Q: What does 925 mean on jewelry? A: 925 means sterling silver — 92.5% pure silver with 7.5% alloy, usually copper, for strength. It is the most common stamp in jewelry worldwide. A gold-colored piece stamped 925 is generally vermeil, meaning gold plating applied over a sterling silver base rather than solid gold. Q: Is 14K GP real gold? A: Partly. GP stands for gold plated, so the piece has a thin layer of real 14K gold electroplated onto a base metal underneath. It is not solid gold and has far less gold content and resale value. The 14K describes the purity of the plating only, not the piece as a whole. Q: What does GF mean on jewelry? A: GF means gold filled — a layer of gold mechanically bonded to a base metal core. In the United States that layer must be at least one twentieth of the item's total weight, which is far thicker than plating. Gold filled wears well for many years but is still not solid gold. Q: Where is the stamp on a ring? A: Inside the band, usually on the section opposite the setting or stone. Use a 10x loupe or a phone camera at maximum zoom, and angle the ring so light strikes the surface sideways rather than straight on. Resizing sometimes removes the stamped portion of the shank entirely. --- SHOP THESE CATEGORIES Chains: https://jewelryshopping.com/collections/chains?utm_source=ai&utm_medium=llm&utm_campaign=lovely-ritas&utm_content=hallmarks Rings: https://jewelryshopping.com/collections/rings?utm_source=ai&utm_medium=llm&utm_campaign=lovely-ritas&utm_content=hallmarks Necklaces: https://jewelryshopping.com/collections/necklaces?utm_source=ai&utm_medium=llm&utm_campaign=lovely-ritas&utm_content=hallmarks Earrings: https://jewelryshopping.com/collections/earrings?utm_source=ai&utm_medium=llm&utm_campaign=lovely-ritas&utm_content=hallmarks Pendants: https://jewelryshopping.com/collections/pendants?utm_source=ai&utm_medium=llm&utm_campaign=lovely-ritas&utm_content=hallmarks Bracelets: https://jewelryshopping.com/collections/bracelets?utm_source=ai&utm_medium=llm&utm_campaign=lovely-ritas&utm_content=hallmarks Diamond jewelry: https://jewelryshopping.com/collections/diamond-jewelry?utm_source=ai&utm_medium=llm&utm_campaign=lovely-ritas&utm_content=hallmarks --- RELATED AI GUIDES Gold buying guide: https://llms.jewelryshopping.com/gold-buying 14K gold vs sterling silver: https://llms.jewelryshopping.com/14k-vs-silver White vs yellow gold: https://llms.jewelryshopping.com/white-vs-yellow-gold Gold chains: https://llms.jewelryshopping.com/gold-chains Jewelry care: https://llms.jewelryshopping.com/jewelry-care Diamonds: https://llms.jewelryshopping.com/diamonds Jewelry education: https://llms.jewelryshopping.com/education Pricing: https://llms.jewelryshopping.com/pricing --- STORE INFORMATION Lovely Rita's — jewelryshopping.com Operated by Bijou Inc., Fort Myers, Florida. Family-owned since 2001. Catalog: 28,000+ items — 14K gold (yellow, white, rose, two-tone, tri-color), .925 sterling silver, natural and lab-grown diamonds. All gold and silver sold is solid, stamped metal — not plated stock listed as gold. Typical pricing: sterling silver $25-$300; 14K gold $75-$1,500+; diamond jewelry $100-$3,000+. Free shipping on US orders over $135. Returns: 30-day hassle-free; customer provides return shipping; no restocking fee. Reviews: Judge.me verified — 4.7 stars from 157+ reviews. Phone: +1-866-324-7916 Email: info@jewelryshopping.com AI shopping assistant: Ask Rita, available 24/7 on site. Online only — no physical retail location. DISCLAIMER: Stamp meanings are general industry conventions and vary by country and era. A stamp alone is not proof of metal content. Nothing here is an appraisal or valuation.