A green mark on skin usually means a copper-bearing layer has reacted at the surface and transferred colored residue. That is different from a red, itchy rash, which may be allergic contact dermatitis and can involve nickel or another allergen. It is also different from ordinary tarnish on the jewelry itself.
For a wholesale buyer, “PVD,” “gold plated,” or “anti-tarnish” is not a complete specification. Color retention depends on the substrate, every intermediate layer, surface preparation, coating material, thickness, topcoat, geometry, wear point, and care conditions. The practical job is to lock those details before samples and verify the finished sample against the same written specification.
Quick diagnosis: green mark, tarnish, or allergy?
| What you observe | Likely direction to investigate | What it does not prove |
|---|---|---|
| Green or blue-green residue on skin | Copper or a copper-rich alloy may be exposed through pores, wear, or an uncoated surface | It does not identify the complete alloy or coating stack |
| Darkening on the jewelry surface | Tarnish, chemical exposure, surface contamination, or coating wear | It does not automatically mean the piece is unsafe |
| Redness, itching, or a rash | Possible skin sensitivity or allergic contact dermatitis; nickel is a common jewelry exposure | A green residue alone is not a medical diagnosis |
| Flaking or bare high-contact edges | Poor adhesion, inadequate preparation, a brittle layer, or normal wear through a thin coating | It does not reveal the coating thickness without measurement |
If a wearer has persistent irritation, the correct next step is medical advice—not a marketing claim about “hypoallergenic” jewelry. For the purchase order, treat discoloration and sensitization as separate risks with separate evidence.
Why plated jewelry can turn skin green
Copper-containing substrates such as brass are common in fashion jewelry. Copper corrosion products can be green or blue-green. When the decorative layer is porous, damaged, poorly adhered, or worn through, moisture and skin-contact conditions can reach an underlying copper-bearing layer. Residue may then transfer to skin.
The visible result depends on more than the final color layer:
- Base metal: brass, zinc alloy, stainless steel, sterling silver, and other substrates behave differently.
- Surface preparation: oil, polishing compound, scale, or an unstable oxide can weaken adhesion.
- Barrier or strike layer: the intermediate stack can affect corrosion resistance, adhesion, color, and nickel exposure.
- Decorative coating: gold alloy, rhodium, nitride, or another coating creates appearance but does not erase the behavior of the substrate.
- Topcoat or sealer: a clear layer may help in a defined system, but “protective coating” without chemistry and cure details is not a specification.
- Use conditions: rings, bracelets, clasps, and necklace contact points face different friction, sweat, cosmetic, and cleaning exposure.
That is why two pieces described as “18K gold plated” can perform differently. The phrase names an appearance or coating claim; it does not disclose the substrate, layer stack, measured thickness, adhesion, or test result.
PVD and electroplating are processes, not durability guarantees
Electroplating
Electroplating deposits a metal layer from an electrolytic bath using electrical current. It can apply genuine precious-metal layers and gives manufacturers substantial control over finish and thickness when the bath, pretreatment, current, time, geometry, and quality controls are defined.
FTC consumer guidance notes that plated gold eventually wears and that wear depends on how the article is used and the plating thickness. That is a useful boundary: a process name or color does not provide a service-life promise.
PVD
Physical vapor deposition forms a thin coating in a vacuum or low-pressure environment. Decorative PVD systems can provide hard, wear-resistant finishes and a wide range of colors. But PVD is not automatically “chemical-free,” “pollution-free,” or permanent. Peer-reviewed reviews show that substrate hardness, cleaning, adhesion layers, corrosion-resistant underlayers, coating composition, geometry, and the full process stack all affect performance. Hybrid electrochemical-plus-PVD stacks are also used.
A PVD label therefore needs the same buyer discipline as an electroplating label. Ask what was coated, what layers sit below the visible finish, how thickness is measured, and what acceptance test applies.
What to put in a plated-jewelry RFQ
Use one comparable specification for every supplier. At minimum, request:
| RFQ field | What the supplier should state |
|---|---|
| Product and high-wear locations | Ring, chain, clasp, earring post, bracelet, pendant; identify edges and contact points |
| Base metal | Exact substrate or alloy designation, not “premium alloy” |
| Surface preparation | Cleaning, polishing, activation, and any pretreatment relevant to the process |
| Complete layer stack | Substrate → strike/barrier layers → decorative layer → topcoat/sealer |
| Coating process | Electroplating, PVD variant, or a hybrid process; do not accept “vacuum gold” without clarification |
| Coating material and color | Material/fineness claim plus an approved physical color reference |
| Target thickness | Target, tolerance, measurement locations, and whether each layer or only total thickness is measured |
| Measurement method | Lab or factory method, instrument, calibration/reference standard, and report format |
| Skin-contact requirement | Destination-specific nickel release or other restricted-substance requirement |
| Sample and bulk test plan | Which checks apply to the approved sample and which are repeated by batch |
| Packaging and care statement | Individual protection, anti-scratch handling, and buyer-approved care language |
Do not accept a quotation that says only “PVD, 18K, never fades.” Replace it with measured fields and pass/fail criteria. If the supplier cannot state the layer stack, the buyer cannot tell which variable changed when the bulk order fails.
Thickness matters, but the number must be measurable
Thicker is not a universal promise of better jewelry. A thicker layer with poor adhesion can still peel. A hard coating on a soft substrate can crack or deform at high-contact points. Geometry can also produce uneven coverage around edges, recesses, clasps, and chain links.
Specify four items together:
- target thickness;
- allowed tolerance;
- measurement locations;
- measurement method.
ASTM B568 describes X-ray spectrometry as a non-contact, nondestructive coating-thickness method for suitable coating/substrate combinations. Its usefulness depends on the materials, thickness range, calibration, and instrument setup. Ask the lab to name the method and report the actual locations tested. A supplier screenshot with one number and no sample identity is weak evidence.
For gold-plated products sold in the United States, FTC terminology also matters. The FTC explains that “gold electroplate” describes an electrolytically applied gold layer meeting its stated fineness and thickness condition. Marketing terminology and your private quality specification are related but not interchangeable: your RFQ may need a stricter stack or test plan for the intended use.
Nickel: check release, not a blanket “nickel banned” claim
Nickel in jewelry is a skin-contact and compliance issue, but saying “nickel is banned” is inaccurate. The relevant rule can depend on the destination, product part, contact pattern, coating, and release rate.
For EU products intended for direct and prolonged skin contact, REACH Annex XVII sets nickel-release conditions for items such as earrings, necklaces, bracelets, chains, anklets, rings, watch cases, straps, and similar parts. The cited rule uses a release threshold and also addresses non-nickel coatings over nickel-containing parts. Confirm the current consolidated rule and applicable test method for the exact SKU.
Nickel allergy is also a real health issue. The American Academy of Dermatology identifies nickel as a common cause of allergic contact dermatitis and jewelry as a common exposure source. Keep this separate from green staining: a buyer should not diagnose either condition from color alone.
For an EU-bound RFQ, ask for:
- the exact skin-contact parts covered by the test;
- the current applicable nickel-release method and acceptance limit;
- report number, sample identity, test date, and laboratory;
- whether the tested sample has the same substrate, layer stack, topcoat, and geometry as the order;
- a change-control rule requiring approval before any material or process substitution.
Build a sample test plan that matches the claim
A useful sample plan combines appearance, construction, measurement, and exposure controls.
Visual and dimensional baseline
Photograph the approved sample under fixed lighting. Record color reference, gloss, coverage at edges/recesses, dimensions, weight, clasp action, and any approved variation. Keep the sample or seal a signed photo/spec record.
Coating thickness and composition
Use a method suitable for the layer/substrate combination. Record measurement points instead of reporting only an average. If the piece contains several layers, confirm what the instrument can distinguish and what it cannot.
Adhesion and wear
Define a repeatable factory or lab method with a pass/fail endpoint. High-contact items may need an abrasion or wear simulation rather than a static appearance check. Do not convert one test result into “will last two years” unless a validated correlation for that exact system exists.
Artificial-sweat or nickel-release testing
Use the destination requirement and actual skin-contact parts. The report should identify the finished sample, not only a raw metal coupon.
Salt spray
ASTM B117 provides a controlled environment for relative corrosion-resistance information. ASTM also states that standalone salt-spray results have seldom correlated with performance in natural environments and do not prescribe a universal exposure period or interpretation. Use it only with a named method, hours, specimen preparation, and acceptance criteria. Do not translate “48 hours passed” into months or years of wear.
Approve the sample, then control the bulk order
Before payment, bind the purchase order to:
- approved sample ID and dated photos;
- exact substrate and layer stack;
- coating material, color reference, target thickness, tolerance, and measurement points;
- required test methods and acceptance limits;
- packaging and care-label wording;
- no-substitution/change-control clause;
- inspection sampling and report handoff.
At receiving or pre-shipment inspection, confirm the purchase-order identity first. Then compare color, high-wear locations, finish, dimensions, packaging, and required test documents. A report from an earlier order or a different geometry is reference material, not proof for the current batch.
For base-metal selection, keep the detailed decision with our jewelry material guide. For the broader import workflow, use the fashion jewelry import guide. This page stays focused on plating failure, specification, and verification.
A practical buyer decision
Choose a coating system from the product’s use case, not from a slogan.
- For frequent skin contact or friction, require a complete stack and evidence for the high-wear points.
- For an EU-bound skin-contact product, build the nickel-release requirement into the RFQ and test the finished geometry.
- For color-sensitive private-label work, approve a physical reference and control batch-to-batch variation.
- For a first supplier, treat samples and method-bound tests as pre-payment evidence.
PVD can be a strong option; electroplating can also be the correct option. In some constructions, a hybrid stack is deliberate. The defensible choice is the one a supplier can describe, measure, reproduce, and document.
How Style Sourcing can help
Style Sourcing can help overseas buyers communicate a plating specification to Chinese suppliers, compare quotations and layer-stack answers, follow up on samples, coordinate inspection/testing, consolidate goods, and hand the order to the freight process. Send the product type, substrate, target color, destination, expected quantity, skin-contact parts, and required test documents so the supplier comparison starts from the same brief.
FAQ: jewelry plating and green marks
Does green skin always mean a nickel allergy?
No. A green residue can point toward copper-bearing material at the surface, while nickel allergy commonly presents as an itchy or irritated rash. Neither should be diagnosed from a photo alone.
Is PVD always better than electroplating?
No. PVD and electroplating have different strengths and limitations. Performance depends on the substrate, pretreatment, underlayers, coating composition, thickness, geometry, and use. Ask for the complete stack and test evidence.
How many microns should I specify?
There is no universal number for every product. Define the substrate, process, coating material, use case, tolerance, measurement points, and method. Then validate the sample and set a batch acceptance rule.
Does passing a salt-spray test prove years of wear?
No. Salt spray can compare corrosion behavior under a defined chamber condition, but it should not be converted directly into consumer wear life without a validated correlation.
What should I ask for before paying a supplier?
Ask for the complete material/layer specification, measured sample results, destination-specific restricted-substance evidence, approved sample identity, packaging details, change-control agreement, and batch inspection plan.
Sources and evidence boundaries
- FTC: Buying Platinum, Gold, and Silver Jewelry
- ECHA: Annex XVII nickel restriction
- EUR-Lex: nickel restrictions for skin-contact products
- American Academy of Dermatology: nickel allergy
- Peer-reviewed comparison of electroplating and PVD finishing
- Peer-reviewed decorative PVD review
- ASTM B568 coating-thickness method
- ASTM B117 salt-spray scope and limitations
Requirements vary by destination and product. Confirm the current law, test method, and responsible economic operator for the exact SKU. This article is a sourcing-control guide, not medical or legal advice.
