Most costume jewelry is worth very little, and some of it sells for hundreds of dollars. The problem for anyone holding a full jewelry box is that the two look nearly identical sitting side by side, and the pieces people assume are worthless are frequently the ones that matter. A quick pass through the box with a magnifier and a few clear rules will tell you whether a trip to a buyer is worth your time.
What Separates Costume Jewelry From Fine Jewelry
Fine jewelry is made from precious metal, gold, platinum, or sterling silver, and set with genuine stones. Costume jewelry is built from base metals such as brass, copper, and zinc alloys, often plated with a thin layer of gold or silver, and set with glass, rhinestones, plastic, or simulated pearls.
That difference determines where value comes from. Fine jewelry carries a floor price tied to its metal weight and stone quality, so it always has some worth even when broken. Costume jewelry has no metal floor worth mentioning. Its value comes entirely from who made it, when, how well it was built, and whether collectors want it right now.
Weight and feel give you a quick read. Precious metal has heft that plated base metal does not. Green marks on the skin, flaking at the wear points, or corrosion around the edges point to plated base metal. A magnet is useful too, since gold, silver, and platinum are not magnetic, though plenty of non-magnetic base metals exist as well.
Where to Look for Hallmarks and Metal Stamps
Check the inside of ring shanks and bangles, the posts and backs of earrings, and the clasp or the small tag near it on chains and bracelets. Use a magnifier and good light, since these marks are tiny and often worn.
Gold is stamped 10K, 14K, 18K, or 22K in the United States, and 375, 585, 750, or 916 in the European fineness system. Sterling silver is marked 925 or the word sterling. Platinum shows PLAT, 900, or 950. Any of those stamps moves the piece into a different conversation immediately.
Marks that indicate plating are just as informative. GF means gold filled, GP or HGP means gold plated, and GE means gold electroplate. Gold filled carries a thicker layer than plating and holds a small amount of value in volume, but neither approaches solid karat gold. An unmarked clasp usually signals costume construction, though very old pieces sometimes lost their marks to wear.
Costume Makers That Collectors Still Pay Real Money For
A maker’s signature is what turns costume jewelry from clutter into a sale. The mid-twentieth century was the industry’s high point, and the names from that era still draw active collectors. Trifari, Miriam Haskell, Kenneth Jay Lane, Sarah Coventry, Weiss, Eisenberg, Coro, and Schiaparelli all have followings. Costume lines from fashion houses such as Chanel and Christian Dior sit at the top of the market. Strong signed pieces from desirable makers regularly bring anywhere from fifty dollars into the low thousands.
Unsigned pieces are not automatically worthless. Collectors respond to good design, unusual figural brooches, and quality glass regardless of whether a mark is present, and some well-known makers left many pieces unmarked. What sells is design and condition rather than the signature alone.
What Construction and Condition Tell You About Quality
Look at how the stones are held. Better costume jewelry uses prongs the way fine jewelry does, and cheaper work glues stones into place. Glue residue, cloudy stones, and empty settings all pull value down hard.
Examine the details. Crisp casting, even prongs, clean lines, secure joints, and a well-made pin mechanism on a brooch all point toward a quality maker. Sloppy seams, rough edges, and dull uniform surfaces do not. Condition carries extra weight here because most costume jewelry cannot be repaired. The heat needed to solder brass or copper would ruin the plating, so a broken piece generally stays broken.
Sorting a Mixed Jewelry Box Without Throwing Out the Good Pieces
Work through the box slowly and put anything with a metal stamp, a maker’s mark, or a stone that might be genuine into a separate pile. Everything unmarked but well made goes into a second pile rather than the trash. Skip the home tests that involve vinegar, bleach, or scratching the piece against stone, since those can permanently damage something valuable and rarely settle the question anyway.
Bring both piles rather than only the first. Households across Staten Island turn up real gold and diamonds mixed into boxes of costume pieces, usually because a grandmother kept everything together in one place and nobody sorted it afterward. Testing takes a few minutes per item and gives you an answer that guesswork will not.
If you have a box you have been meaning to go through for years, bring the whole thing to Collectors Coin & Jewelry in Staten Island and have it examined in person, so you know what is real before anything gets donated or discarded.