Holiday sales are when the most jewelry changes hands, and when look-alikes are easiest to pass off. Most of what you need to check takes a few minutes at the counter or on a listing: the stamp, the metal, the stone and the paperwork.
What our scans show
11%
of jewelry scans read as plated or base metal, not solid gold, silver or platinum
1 in 6
jewelry scans read as diamond were set in silver or plated metal, where a clear stone is far more often cubic zirconia or moissanite
Cubic zirconia is the fifth most scanned stone in jewelry, after diamond, sapphire, emerald and ruby.
From about 6,400 scans by about 2,100 people in the GemstoneAI app, January 21 to October 31, 2026, with test and staff accounts left out. Values are first-read estimates from photos, not appraisals.
1. Read the stamp, then back it up
Solid gold is marked with its karat: 10K or 417, 14K or 585, 18K or 750. Sterling silver is 925 or STER, platinum PT950 or PLAT. Stamps such as GP, GEP, HGE, GF or RGP mean a gold layer over another metal.
A stamp is a claim, not proof. Stamps are easy to fake, so back one up with a second check below. See every jewelry stamp.
2. Check the metal
A magnet. Gold, silver and platinum are not magnetic. If a magnet pulls the body of a ring or chain (not the clasp), it is not solid precious metal. A magnet that does not pull rules out steel, not brass.
Worn edges. A different color at the edges, the clasp or the underside of a ring means a plating over another metal.
The price per gram. Ask the weight. At today's prices 14K gold holds about $76.28 of metal per gram, so a 10 gram 14K chain holds about $762.78 of gold. A price below the metal it claims to contain means it is not that metal. Use the melt value calculator.
A "diamond" in silver or plated metal is usually cubic zirconia or moissanite. Diamonds are usually set in gold or platinum.
Too perfect for the price. A large, clean, vividly colored stone at a low price is usually lab-made, glass or heavily treated. Natural stones of that quality are rare and priced to match.
Treatments. Many rubies and sapphires are heated and many emeralds are oiled. In the US, the FTC's Jewelry Guides say a seller should disclose a treatment that is not permanent, needs special care, or significantly affects the stone's value (16 CFR 23.24). Ask, and get the answer on the receipt.
Lab-grown or natural diamond. No look test separates them. Ask for the lab report. See lab-grown vs natural diamond.
4. Ask for paperwork and a return window
For a diamond of about half a carat or more, ask for the lab report, and look the report number up on the lab's own website.
Have the metal, the stone and any treatment written on the receipt.
Know the return policy before you pay, especially on marketplaces, at estate sales and at pawn shops.
5. Scan it before you pay
Photograph it with GemstoneAI at the counter, or scan the listing photos. You get a first read on the stone, the metal and what it is likely worth, so you know whether the price makes sense. It is a first read from photos, not an appraisal. For an expensive purchase, have it appraised independently inside the return window.
Check it before you pay
Photograph any ring, necklace or loose stone and GemstoneAI identifies the stone and the metal and gives a first read on its value. Your first scan is free.
Yes. Stamps are easy to fake, so back a stamp up with a second check: a magnet, a look at worn edges, the price per gram, or a jeweler's test.
How can I tell if a diamond is real when I buy it?
Look at the setting first: a clear stone in silver or plated metal is usually cubic zirconia or moissanite. For a diamond of any size, ask for the lab report and check its number on the lab's website. No look test separates a lab-grown diamond from a natural one.
Can I check jewelry from an online listing?
Yes. Ask for a clear photo of the stamp and the weight in grams, compare the price with the metal value, and scan the listing photos with GemstoneAI for a first read before you pay.