Demystifying Jewelry Hallmarks and XRF Testing

Sep 11, 2025

Shopping for fine jewelry should feel exciting—not uncertain. If you’ve ever squinted at tiny stamps or wondered whether a piece is truly what the seller says it is, this guide is for you. Below, we demystify jewelry hallmarks, show how modern XRF jewelry testing works (the non‑destructive lab method we use at Zalori), and give you a practical checklist so you can buy with confidence and enjoy your pieces for years.

What are jewelry hallmarks—and why should you care?

A hallmark (or quality mark) is a small stamp that tells you the metal and its purity. In the U.S., the Federal Trade Commission’s Jewelry Guides outline how marketers should describe precious metal content so shoppers aren’t misled. If a piece is marked for precious metal quality, sellers are expected to use accurate terminology and avoid deceptive claims about gold, silver, platinum, and surface treatments like rhodium. You don’t need to memorize the legal text, but knowing that standards exist—and glancing for a clear, legible mark—goes a long way toward stress‑free buying. See the FTC’s Guides at 16 CFR Part 23 for the official framework (plain‑English takeaway: say what it is, and say it clearly).

Hallmark cheat sheet (gold, silver, platinum)

Use this quick reference when you’re inspecting a clasp, inner shank, or tag.

Gold (karat marks): 24K (pure), 22K, 18K, 14K, 10K. International “parts‑per‑thousand” equivalents you may see include 999 (24K), 917 (22K), 750 (18K), 585 (14K), 417 (10K). GIA summarizes karat as “parts out of 24,” and explains how alloying adjusts color and durability.
Silver: “925,” “.925,” or “STERLING” indicates sterling silver (92.5% silver). Learn how to spot and care for sterling in our in‑depth post, “ Is Your Silver Chain 925?
Platinum: Common stamps include 950 Pt, 900 Pt, or Pt followed by alloy letters (e.g., 950 Pt Ru or 950 Pt Co). GIA’s quality benchmarks show why different platinum alloys are marked distinctly and why matching alloys matters for service.

Tip: A country or maker’s mark (e.g., “ITALY” plus a trademark) can appear alongside purity marks. U.S. rules also address how to label surface coatings and multi‑metal items, so “gold‑plated” shouldn’t masquerade as “gold.” When in doubt, ask the seller to explain every mark in plain language.

How XRF jewelry testing works (and why it builds trust)

Hallmarks are helpful, but they’re only part of the truth. X-ray fluorescence (XRF) testing reads a metal’s elemental makeup in seconds—without scratching, slicing, or filing your jewelry. A handheld instrument directs a tiny X‑ray beam at the surface; atoms in the piece emit signature energies that the analyzer converts into a composition readout (for example, Au 58.5%, Ag 8%, Cu 33.5% for a 14K‑type alloy). Leading manufacturers publish accuracy data showing close agreement between XRF results and certified alloy standards, which is why jewelers, appraisers, and even customs agencies rely on it for screening precious metals. In short: XRF is fast, non‑destructive, and trustworthy when used by trained professionals.

Important limitations (so you stay realistic)

No test is perfect. Because XRF primarily reads the surface, heavy plating or electroformed shells can mask a base material. GIA has documented cases where thickly electroformed gold over a non‑gold core looked convincing until deeper analysis uncovered the truth—an example of why responsible sellers combine techniques and disclose coatings. The practical takeaway: XRF is outstanding for solid alloys and typical vermeil/plated items; if something appears unusually light for its size or shows suspicious construction, a professional may add cross‑checks (density/weight, magnified inspection, or lab verification) before rendering a final judgment.

How we authenticate at Zalori (and why it benefits you)

We invest in professional XRF testing because your peace of mind matters. When you see karat or sterling claims on Zalori pieces, those claims are supported by in‑house screening on a Vanta handheld analyzer, plus old‑school bench inspection. That means:

Non‑destructive verification of gold, sterling silver, and platinum alloys.
Sensible cross‑checks when a piece looks plated, electroformed, or unusually light for its dimensions.
Clear descriptions that follow industry guidance—so you aren’t surprised later by upkeep like rhodium replating on white metals.

If you’re comparing karats, our guide 14K vs 18K vs 24K Gold explains purity, color, and durability trade‑offs in everyday wear (including when white gold may need rhodium touch‑ups). Prefer sterling? Start with Is Your Silver Chain 925? and then bookmark Sterling Silver Care 2025 for low‑effort, non‑harsh cleaning.

Spot‑check table: what the stamp should say vs. what XRF typically shows

Metal	Stamp	XRF Reading
14K gold	“14K” or “585”	Around Au 58% ± normal alloying metals (Ag/Cu/Zn).
18K gold	“18K” or “750”	Around Au 75% with balance metals.
Sterling silver	“925” or “STERLING”	Around Ag 92.5% with copper remainder.
Platinum jewelry	“950 Pt [alloy]” or “900 Pt [alloy]”	Shows 90–95% Pt with ruthenium or cobalt, etc.

Red flags to investigate further

Mixed or conflicting marks (e.g., “14K” and “18K” on the same ring without explanation). Sometimes two bands were soldered together—but it’s still worth a pro inspection.
Missing maker’s mark alongside a purity stamp when one should be present.
Extremely low weight for the size; very light, bulky pieces can indicate hollow construction or electroforming.
A bright “white” gold look that quickly dulls to yellow—likely thinning rhodium plating.

Real‑world buying checklist (use this before you click “Add to cart”)

Find the hallmark and read it: 14K/18K/24K or 585/750/999 for gold; 925/STERLING for silver; 950/900 Pt for platinum. If you can’t find a mark on a claimed precious‑metal piece, ask for documentation.
Skim the seller’s descriptions: Are plating, vermeil, or coatings disclosed? U.S. guidelines call for transparent, non‑deceptive labeling of precious metal content and surface layers.
Ask about testing: Reputable sellers can explain how they verify metals. At Zalori, we screen in‑house with a professional XRF analyzer for quick, non‑destructive confirmation.
Sense‑check weight and construction: Does the heft feel right for the size? Are links crisp, clasps secure, and finishing clean?
Keep care in mind: White gold often needs rhodium refreshes over time; sterling rewards simple, consistent care.

FAQ: quick answers for confident decisions

Will XRF jewelry testing damage my piece? No—XRF is non‑destructive and takes seconds.
Can XRF spot plating? It can often detect thin plating (for example, when the analyzer’s “plating alert” or layered readings trigger), but thick electroformed shells may need additional evaluation. That’s why trained pros combine methods when something looks off.
What if my piece is stamped “585” but XRF reads slightly under 58.5%? Small variances happen depending on where the beam hits (surface vs. inner alloy) and normal manufacturing tolerances. The big picture should still align with the mark.
What does “vermeil” mean? In short, vermeil is a precious‑metal term in which gold is plated over sterling silver to defined thicknesses. U.S. guidance addresses how to use the term so it isn’t confused with solid gold.
Which gold karat is best for everyday wear? 14K is a balanced, durable choice; 18K offers richer color with slightly softer wear. Our 14K vs 18K vs 24K Gold guide breaks this down for daily rings, bracelets, necklaces, and earrings.
How do I care for sterling silver so it stays bright? Keep it dry, store airtight, and use mild soap and water when needed. See our Sterling Silver Care 2025 tutorial for a simple, sustainable routine.

Style and substance: choosing pieces you’ll love longer

Once you understand hallmarks and how we test, you can shop creatively with confidence. If you’re leaning silver, explore the sculptural foxtail and Balinese weaves in our Men’s Bracelets collection—they’re artisan‑made in real sterling and designed to age beautifully with your wardrobe. Prefer the warmth of gold? Our handcrafted 18K options deliver the heirloom glow and satisfying weight that fans of higher karat love (with the care transparency you deserve).

Pro move: pair knowledge with fit

Authenticity matters—but so does comfort. If you’re shopping bracelets, measure your wrist and add the right increment for the weave (our product pages note suggested sizing). For rings, request the exact inner‑diameter size or consult our virtual team, and remember that wider bands can feel tighter. Small fit details mean you’ll actually wear what you buy—sustainability in action.

Your next step (we’ll help)

See real‑metal, artisan pieces without second‑guessing: browse our Men’s Bracelets edit for hand‑braided Bali, foxtail, and Thai weaves.
Want a quick karat refresh? Skim 14K vs 18K vs 24K Gold for the practical differences in color, wear, and upkeep.
Need silver‑care receipts? Save our Sterling Silver Care 2025 checklist.
Prefer one‑on‑one guidance? Book a complimentary virtual appointment and we’ll walk you through metals, marks, and fits before you buy.

When you combine honest hallmarks, XRF‑backed verification, and clear care tips, you end up with jewelry that looks incredible today—and still feels like a smart decision years from now.

Helpful links (for deeper reading and standards)

FTC Jewelry Guides (16 CFR Part 23) — the U.S. framework for precious‑metal marketing and quality marks.
GIA on gold purity and metal choices — plain‑English intros to karat, alloys, and everyday wear.
GIA case study on electroformed gold — a reminder that thick shells can fool surface‑only checks.
XRF for precious metals — how handheld analyzers measure composition quickly and non‑destructively.