Updated October 30, 2020:

Jewelry Trademarks

Jewelry trademarks help protect the names, logos, or initials of jewelry manufacturers, importers, wholesalers, or retailers. They're registered with the United States Patent Office (USPTO), or a similar organization in another country.

A maker's mark is an unregistered trademark. Both types of trademarks have been used on fine and costume jewelry for hundreds of years. Some companies have changed their marks since their founding, and the law on jewelry trademarks varies in different countries. A trademark or maker's mark is like a signature, letting customers know who made a piece of jewelry.

Finding Marks on Jewelry

Used jewelry is a big seller for many jewelers and other small businesses, and trademarks and maker's marks help them establish value. Stamps often specify the metals used to make the jewelry along with the manufacturer. Fine jewelry is usually made from precious metals and gemstones while costume jewelry is constructed from a base metal, like stainless steel, that's coated with gold or silver. It's set with imitation gems like cubic zirconia or semiprecious stones like hematite or quartz.

Not all jewelry has a trademark, maker's mark, or stamp, but a professional usually look for these marks as part of an appraisal. They can be tiny, so magnification is often used. You should look for letters, words, or numbers inside rings, on the backs or undersides of pendants, on the clasps of bracelets, and on the backs or posts of earrings. Use a jeweler's loupe that can magnify at least 10 times and check the marks you find from a few different directions to make sure you're not looking at anything that's upside down. In addition to the trademark or maker's mark, you might see:

  • A purity mark
  • A date letter
  • A town mark

A date letter tells people where and when an item was made. Jewelry that was assayed in a country with more than one trademark or patent office has a town mark to indicate the office of assay. In some European countries, jewelry manufacturers must include purity and makers' marks on all silver or gold jewelry. The United States doesn't require marks on jewelry, but any marks that manufacturers add are protected by trademark laws.

Trademark and Maker's Mark in Jewelry

A maker's mark is the same as a maker's signature. In some European countries, jewelry is required to not only have marks for purity, but also a maker's mark. The U.S. does not require the maker's marks and typically only require a trademark to protect intellectual property.

In countries where maker's marks are required, jewelry and watchmakers are required to register their marks so that the piece of jewelry can be tracked if necessary. The mark acts as a personal trademark, providing information on who is responsible for the content of precious metal in the piece.

Identifying Value of the Jewelry

There are many factors that go into determining the value of jewelry, such as:

  • The type of metal the jewelry is made from.
  • The date the jewelry was made.

Hallmarks

Also known as purity or quality marks, hallmarks are the most common stamps on jewelry. They're required for all the jewelry that's made in some countries. In those countries, an assay office tests each piece and then adds their official stamp or hallmark. This is similar to the way diamonds are certified by the Gemological Institute of America (or GIA) in the United States. Assay offices also test many watches. However, some countries don't have hallmarks, and others like Norway and Austria have optional hallmarking.

Hallmarks identify the amounts of precious metals in fine jewelry, and they describe the way gold or silver was applied to another metal in costume jewelry. Since they've been used for hundreds of years, they vary by country and time period.

What Can Hallmarks in Jewelries Tell You?

A jewelry hallmark can also sometimes tell you when and where the jewelry was made. In countries where there is an assay system in place, fine jewelry and watches cannot be sold without a hallmark. Tiffany & Company sends its pieces to London to get these hallmarks.

The United Kingdom belongs to the Hallmarking Convention along with 18 other countries. The convention helps to create the standards for jewelry testing so that a piece does not require testing every time it crosses into another country. There are some countries in Europe that either don't have or don't require hallmarks. Germany does not have hallmarks; Italy does not use hallmarks but has a different formal system.

Fine jewelry that is made in the United States typically will have a mark to denote the content of precious metal, but there is no set system in places so these are not always accurate. While this is not typical for large or established brands, "under-karating" can be common with mass-market manufacturers. An appraiser can help you decipher these marks, which are similar to a data letter, so you can determine where and when a watch or a piece of jewelry was made.

The Meanings of Common Marks

Here are some of the most common hallmarks or purity marks:

  • Platinum is usually stamped with the abbreviation PLAT or PT.
  • Gold-filled jewelry is covered with a layer of at least 10-karat gold, and it's often stamped with G.F. or R.G.F.
  • G.E. stands for Gold Electroplate.
  • Pure gold is 24 karats, and it's stamped with 999 or 24k.
  • 20-karat gold is stamped with 833 for its 20 to 24 or .833 gold to alloy ratio.
  • Sterling silver is usually marked with Sterling or 925 because it's 92.5 percent pure.

Carat versus Karat

A carat is the weight of a diamond or another gemstone, and it's equal to 200 milligrams. A karat measures the purity of gold, and a 14-karat gold item has 14 out of 24 parts gold. It's usually stamped with "14k" in an inconspicuous place. Gold jewelry is usually an alloy, a mixture of gold and another metal.

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