Next time you’re going through an old box of ornamental, seemingly cheap and worthless jewelry, you might want to take another look (or better yet, have a jewelry appraisal expert take a look)—you may be surprised on how much your junk costume jewelry is really worth!

Costume jewelry, by definition, is jewelry crafted from cheaper materials and/or mock gemstones. But according to Erik Hoyer, co-owner of EJ’s Auction & Consignment and J. Levine Auction & Appraisal, there’s a certain style of this vintage jewelry originating from the 1920s and booming in the ‘50s that could be worth a pretty penny, depending on the quality and craftsmanship. Upon a recent visit to a woman’s house to sort through unwanted items for an auction, he thumbed through a box full of jewelry the woman had deemed worthless and made a few surprising discoveries.

“I quickly scanned what she had,” said Hoyer, “…and started pulling out pieces that weren’t, in fact, cheap costume jewelry but actually well-known brands. Some contained 14-karat gold.”

The woman, who’s box of jewelry had been passed down from her grandmother, was quite delighted in finding out that some of her “outdated, junk jewelry” was actually worth hundreds of dollars. And who wouldn’t be?

So before you donate that box of Granny’s old rings and necklaces from the ‘50s to your local Goodwill, you might want to consider having someone experienced in jewelry appraisal to a quick gander at the goods. It doesn’t even have to be gold! Many vintage pieces are worth some serious cash without having any gold in them at all.

You can also scan through the jewelry yourself by looking for a few telling details that may be found on the surface of the item. Firstly, you’ll want to look for a jewelry mark or brand name stamp on the surface of the item. If it has a stamp, it’s possible that it could be high quality. Although, you may need a loupe—a small magnifying device used by jewelers—to be able to see any marks or stamps.

Second, you’ll want to look for any signs of green discoloration. You may even want to slip it on for a day and see if it leaves any residue on your skin after removal. The green is a telltale sign of low quality jewelry, similar to the ones you can get for 50 cents from the quarter machine at the burrito joint down the road. Also look for any delamination or flaking of the surface on the piece—another characteristic of junk jewelry.

And lastly, take a look at the fine details of the item. Again, you may need a jeweler’s loupe to see all the intricacies in grandiose detail. If they tiny aspects and/or patterns look messy or thrown together like a term paper wrote the night before its due date, it’s probably not worth much, if anything. But if the small details are clear and neat and finely tuned, it’s possible that you could be holding some mid to high quality bling.

So think twice before dumping out the goods. Grab those silly earrings you wore when you dressed up as Jasmine from Aladdin for Halloween years ago. Pick through your mother’s box of old tangled necklaces she let you play with as a child. You may have some unknown treasures hiding on top of your dresser. You never know—one person’s trash could be another one’s trip to the Bahamas!