Fdi Stamp: Wedding Band Mystery Solved

Stamps inside wedding bands can be used to identify things like metal content, country of origin, trademarks, and jewellers. The most important mark is usually the metal stamp, or karat weight of the metal. In the United States, gold hallmark stamps are not required on all pieces of gold jewellery, but if a karat stamp is placed on a piece of jewellery, a stamp of the trademark sign is also required. In other countries, hallmark stamps are legally required.

Stamps indicate the type and weight of metal and gemstones

Stamps on jewellery are called hallmarks and they indicate the type and weight of metal and gemstones. Hallmarks are important for authenticating jewellery, especially valuable pieces. They are commonly found on noble or precious metals like gold, platinum, silver, and palladium.

Types of Hallmarks

Purity Marks

The most common type of jewellery hallmark is a purity mark. Purity marks, also called quality marks or standards of fineness, indicate the metal type and purity.

Gold purity is measured in karats, which is different from "carat" weight used for gemstones. Karats are a ratio that tells you how much of the gold is pure gold and how much is additional non-gold metals. Pure, 100 percent gold is 24K (24 karats), so 24 is the maximum in the ratio. 18K gold is 18 parts pure gold to 6 parts other metals, making it 75 percent pure gold. 10K gold is 10 parts gold to 14 parts other metals, making it 41.67 percent pure gold.

Silver purity, or "fineness", is measured similarly to gold but without the karat ratio aspect. Instead, silver purity hallmarks just use the percentage number of pure silver without a decimal point. One of the most well-known silver purity marks is 925, which indicates the metal is 92.5 percent pure. This stamp is usually found on silver jewellery or jewellery that incorporates silver.

Other common numerical hallmarks on jewellery include 825, which means the metal is 82.5 percent pure, and 916, which means the metal is 91.6 percent pure.

Ring Size and Gemstone Weight Marks

Numerical hallmarks may also indicate ring size, with figures like 6, 7, 8, 9, and 10 denoting the ring's size. Rings that incorporate precious gemstones may also have a hallmark indicating the gemstone's weight in carats. The gemstone weight may be etched as the number alone (e.g. "0.75" or ".75" for a gem weighing 0.75 carats), or a number followed by "ct." For multi-diamond rings, jewelers may leave a hallmark indicating the total weight of all the diamonds on the stone with the number followed by "tdw" for "total diamond weight."

Other gemstone-related jewellery hallmarks include:

• CW — Carat Weight (usually of the center stone)
• SD — Solitaire Diamond (a faceted shape)
• CZ — Cubic Zirconia (a synthetic gemstone diamond substitute; usually written after its weight)

Letter Hallmarks

Letter hallmarks can indicate the type of metal used. Common letter jewellery markings that correspond to the type of metal used are:

• P or KP — Plumb Gold (P is usually 14K gold while KP may follow any karatage, e.g. 18KP, to indicate that the gold is that pure or higher)
• PLAT or PT — Platinum
• S.S. or Steel or St. Steel — Stainless Steel
• Silver or S. Silver or STG or STER — Sterling Silver
• Pd or Pall — Palladium

Gold jewellery specifically has its own set of letter hallmarks:

• GF or G.F. — Gold-Filled
• GP or G.P. or HGE or GE — Gold-Plated (also called Gold Electroplated)
• V or HGE — Gold Vermeil (also called Heavy Gold Electroplated)

Sponsor or Maker's Marks

Some jewellery letter markings indicate who made it, often called a "maker's mark." The goldsmith who crafted the jewellery may stamp their initials. The company that makes the jewellery (the jeweller) or the distributing manufacturer may have a "sponsor's mark," like "T & CO." for Tiffany & Co.

Assay Office Symbols

Stamping jewellery to indicate its authenticity is not new, dating back to 1238 AD. Governments and other authorities wanted to ensure buyers knew the true value of the piece they were buying. Authentication hallmarks were typically done by an assay office, where trusted experts inspect the piece and stamp it according to its true characteristics.

Stamps indicate the manufacturer, designer, retailer or jeweller

Stamps inside wedding bands can indicate the manufacturer, designer, retailer, or jeweller. These stamps are often trademarks or signatures that help identify the brand and confirm the ring's quality and characteristics. While there is no universal standard for these seals, they typically include the brand name, initials, or a symbol. For example, Tiffany uses the stamp "T & CO", while J.B. Robinson Jewelers uses "JBR".

The presence of a trademark sign or maker's mark is legally required in some countries, such as the United States, to confirm the gold content in a piece of jewellery. This sign usually represents the company or artist who crafted the ring. In the US, any stamp indicating the karat of the band, such as 10K, 14K, 18K, or 22K, must be accompanied by a trademark sign.

However, it is important to note that the absence of a stamp does not necessarily indicate a lack of authenticity. Antique rings, for instance, may not bear these marks due to differing regulations in the past. Additionally, stamps can fade over time or be altered, so it is always a good idea to have the ring appraised by a professional to confirm its authenticity and quality.

Stamps can be used to trace a ring's origin

Stamps on the inside of a ring can be used to trace its origin. These stamps are usually placed on the inside of the band and can indicate the type of metal, gemstone weight, manufacturer, and trademarks.

The type of metal is often indicated by abbreviations such as "SS" or "St" for stainless steel, "925" or ".950" for sterling silver, and "Pd" or "Pall" for palladium. Gold purity is indicated by a number between 9 and 24 followed by a "K", "kt", or "Kts", with 24-karat gold being completely pure. If a ring is gold-plated rather than solid gold, the stamp will include the abbreviations "GP" or "GF".

The weight of the gemstone is usually indicated by a number followed by "cw" (carat weight), "ct" (carat), or "tdw" (total diamond weight). For example, a stamp of ".55ct" would indicate a diamond of 55 carats.

Manufacturer stamps can include the initials of the manufacturer or designer, or a symbol that identifies a brand. These stamps can be used to trace the origin of the ring back to its source, designer, or retailer. Some well-known manufacturer stamps include "T & Co" for Tiffany & Co. and "© D.Y." for David Yurman.

In addition to these marks, there may be other stamps or symbols that indicate the ring's origin, such as a country abbreviation or a retailer's name. However, it's important to note that there is no universal standard for ring stamps, and some may be difficult to identify, especially if they are from small suppliers, old brands, or unregistered sources.

To aid in identifying these stamps, there are hallmark books and online databases that can be referenced. Additionally, a professional jeweler or appraiser may be able to help identify the stamps and provide more information about the ring's origin and value.

Stamps are not always reliable indicators of authenticity

Stamps on the inside of a ring are meant to summarise valuable information about their quality and characteristics. However, stamps are not always reliable indicators of authenticity.

Firstly, marks can deteriorate over time or with improper treatment of the metal. Maintenance actions, such as polishing the band, may cause some lettering to be lost or unrecognisable. In the case of second-hand rings, it is impossible to be sure that a stone has not been altered, even if the band claims otherwise.

Secondly, stamps can be removed if the jewellery is abused, polished, or coated with metal. Anyone with the right tools can imprint a new stamp. Branded signatures are much harder to forge, but this does not guarantee that other parts of the ring, such as the centre diamond, have not been replaced with worthless imitations.

Thirdly, stamps can be wrong or altered. For example, a ring with the engraving "14KGP", which stands for 14-karat gold-plated, could be buffed out to look like "14KG". In addition, stamps can be hit at the wrong angle, skid when hit, or not make full contact when imprinted.

Therefore, to prevent scams, it is recommended to purchase jewellery from a responsible and recognised supplier, through legal channels that guarantee the authenticity and ethical origin of the materials. If you are considering buying second-hand jewellery, it is more responsible to have it appraised by a professional.

Stamps are not always legally required

Stamps on the inside of wedding bands are not always legally required. While they are mandatory in some countries, they are not required in others. For example, in the United States, gold hallmark stamps are not required on all pieces of gold jewellery. However, if a jeweller places a karat stamp on a piece of jewellery, a stamp of the trademark sign is also required. This trademark sign is usually the sign of the company or artist who made the ring.

The stamps on the inside of wedding bands can include a variety of information, such as the purity level of the metal, carat weight of the diamond, weight of side diamonds, and brand signature. These stamps can be used to identify the manufacturer, type of metal, gemstones, weight, and origin of the ring. However, there is no universal standard for seals, and each manufacturer can use different terminology and symbols.

The type and purity level of the metal are commonly included in the hallmarks. For example, platinum jewellery may be marked as "PT" or "PLAT", while sterling silver may be marked as "Sterling", "925", or ".950". Gold jewellery may be marked with the number of karats, such as "10K", "14K", or "18K".

In addition to the metal type and purity, the weight of the centre gemstone and side diamonds may also be included in the hallmark. This is usually expressed with a period followed by the weight in carats, such as ".55" for a 55-carat diamond.

While stamps on the inside of wedding bands can provide valuable information about the jewellery, they are not always legally required. The specific regulations and requirements can vary depending on the country and the type of metal.

Frequently asked questions