But, it's GOLD! (it's priceless, right?)

You know the scene. You're at a yard sale, sifting through a cookie tin of old Avon pins and single earrings. At the bottom, you find a locket - a pretty, engraved, old locket. You open it up, and sure enough, there's a mark inside! All you can make out is the 14k.. this must be gold! You pay a quarter for your treasure, and dream of the money you'll make reselling your prize.

Now, I'm not going to say this never happens, because it does. It's happened to me a few times - and I've been on the other end a few times, selling things as costume because I misread the marks. But before you rush of to Sothebys to auction off your find, lets take a closer look at those marks.

14KP, 18KP, 18KGP, 14kGEP or variations thereof:
Here the K stands for Karat.. and the P stands for plated. GP is Gold Plated. GEP is Gold Electroplated. There IS gold here, in a layer about a micron thick, over a base of silver or a copper, maybe zinc. Essentially, this is fashion or costume jewelry, meant to look valuable, but having the value of the very small amount of money you paid for it. The gold plating is so thin it wears and chips quickly.

14kGF, 12k GF, 1/20th 12k GF, etc:
Now you're on to something! This jewelry is Gold Filled - and if you're seeing these marks, it means you're probably holding something vintage!
Gold filled jewelry was the high end method of manufacturing costume jewelry in the mid-1900s. Here's a simplified version of how it works:
Picture a double stuffed oreo. Now, picture a bar of gold.   Take that bar of gold, slice it in half, and stuff it with a bar of steel or other base metal (copper, brass) until it looks like a double stuffed oreo. (only, bar shaped, and not a round bit of yumminess.)
Now, take that giant metal oreo and squash it. Squash it again, with a press. When it's thin and flat, do it again. Keep rolling, pressing and flattening until you've achieved a sheet of metal that's about 10 times longer, wider and a 1/10th as thin as your starting oreo. The gold on the outside will be firmly adhered to the basemetal inside, and the layer will be nice and thick. The brass or steel inside gives the piece its stability, while the gold layer outside is thick and will last for years. Voila! Gold Filled Stock, ready to be worked in to lockets, bracelets and earrings.
Gold Filled jewelry works well for people allergic to any but real gold, without having to pay for full gold all the time. It's got a great weight, and it lasts much longer than plated pieces. If melted, Gold Filled pieces usually have a gold content of 3K to 5K.

1/20th 12k GF, for instance, indicates that 1/20th of the metal content is 12k gold.

See something different? Maybe 585, 9ct, 18k p? Well, then, there's gold in that there piece! We'll go over gold content and the associated marks in the next post.