Plumb gold is a technical term that many are not familiar with. Let's go ahead and get you familiarized with what it means!
Up until 1981, in the United States, makers and manufacturers of karated gold jewelry could use gold that was around 13.5 karat (half-karated) and round up, in turn stamping the piece of jewelry 14K. In 1981, the National Gold and Silver Marking Act was passed through the United States Government no longer allowing the round off of half-karated gold. Gold had to be at least 14.0K before it was legally allowed to be stamped 14K. This is plumb gold. 14K means 14.0K or more and 18K means 18.0K or more. Jewelry made from 17.9K jewelry would legally have to be stamped 17K. Some manufacturers now stamp 14KP, for plumb gold. Often times people wrongly assume that this means the piece of jewelry is 14K gold plated. Plated gold is typically marked HGE for heavy gold electroplated or GE for Gold electroplated.
In the United States we mark gold relating to karats. 24K gold is pure (also called Fine Gold). 14K means there is 14 parts out of 24 parts that are gold. The other alloys are 10 parts. This would translate to a 14k Gold piece of jewelry being 58% Gold.
Typically speaking Europeans stamp their gold with the number of parts per thousand. A stamp for 750 (750 parts per thousand) is the marking for 18K gold. In addition 585 stands for 14K gold and 417 is 10K. In the United States, it is not legal to call something gold if it is alloyed below 10K. In England, the limit is 9K so it is common to see a stamp of 375 for 9K on jewelry that originated from there.
Platinum is typically always going to be either 90 percent or 95 percent pure. The marks vary widely, but typically platinum is designated by PL, PT or PLAT or the full word. The marking 950 means 95 percent pure.
Often times it is possible to have jewelry pieces that are actually precious metal with no markings. One possibility is that the stamps were removed during a jeweler doing work on the piece like sizing a ring. Another possibility is the piece was made before 1906, when Congress passed a law requiring jewelry to be properly stamped. If a piece looks Victorian and has no stamp, it was probably made before 1906. The reverse is not necessarily true. Some pieces made before 1906 were stamped. Don't ever throw out unmarked pieces until you have had a chance for a professional to take a look! At Texas Gold and Silver Buyers we utilize non destructive XRF X-Ray Testing to quickly test our customers items in a completely non destructive way. Unlike our competitors who will normally use the destructive Acid Testing method that is also very time consuming and nowhere near exact!
If you have ever seen a ring with some strange numbers in it that do not correlate to the information lined out above, sometimes that is a model number or serial number or manufacturing mark.
Most manufacturers have their own mark that they stamp onto jewelry that they manufacture. For example, Tiffany usually uses Tiffany & Co., but on small items they sometimes stamp T & C.
At Texas Gold and Silver Buyers of San Antonio we are always here to verify your jewelry items and make TOP DOLLAR cash offers on them. But we also have a devotion to inform the public on all the less than known facts and information to do with everything Gold, Silver, Platinum and Palladium.
Feel free to contact us or come by at anytime!
Texas Gold and Silver Buyers
3435 Thousand Oaks Dr.
San Antonio, Texas 78247
Thanks for stopping by our blog. My name is Evan and I am the owner of Texas Gold and Silver Buyers in San Antonio. From time to time I will post blog entries to help educate and inform our customers and potential future customers on all aspects of Precious Metals (Gold, Silver, Platinum & Palladium!)