RINSE AFTER WATER & ACTIVITY
After swimming or exercise, rinse away chlorine, salt and perspiration with clean water, then dry the jewelry completely with a soft cloth.
THE MATERIAL BENEATH THE COLOR
THE COLOR DOESN'T STOP AT THE SURFACE.
Meet S180®—GONA's registered family of color-through, silver-containing jewelry alloys, usually identified on our product pages as Tarnish-Resistant Silver. Real silver is blended throughout three intrinsically colored cores — silver, champagne gold and soft rose gold — then protected by a coordinated multi-layer finish.
REAL SILVER.
DISTINCT FROM 925 STERLING SILVER.
S180® is a genuine silver-containing alloy with real silver present throughout its core. It is a distinct material developed by GONA, not another name or grade of 925 sterling silver.
Our current minimum standard is 20% silver in gold-tone and rose-gold-tone S180, and 25% silver in silver-tone S180. By comparison, 925 sterling silver contains 92.5% silver.
GONA uses both materials for different purposes and identifies S180 clearly as Tarnish-Resistant Silver, so you can always understand what your jewelry is made from.
ONE MATERIAL SYSTEM.
THREE COLOR-THROUGH CORES.
S180 does not begin as one silver-colored base that gains its identity only through plating. Its alloy composition is adjusted so the core itself carries a coordinated silver, champagne-gold or soft rose-gold tone.
Silver-tone
S180®
≥25% silver
S180®
≥25% silver
14K gold-tone
S180®
≥20% silver
S180®
≥20% silver
Rose-gold-tone
S180®
≥20% silver
S180®
≥20% silver
WHY THE CORE COLOR MATTERS
All plated jewelry gradually experiences some loss of surface luster through normal wear, friction and contact with the environment.
With traditional gold- or rose-gold-plated sterling silver, deeper wear can eventually progress through the plated and barrier layers to reveal a silver-colored core. Once exposed, sterling silver may develop a dark gray or charcoal-colored patina.
S180 takes a different approach. Because the alloy itself already carries a coordinated color, natural surface aging reveals a softer silver, champagne-gold or delicate rose-gold tone instead of a sharply contrasting darkened core.
THREE COLOR-MATCHED CORES. THREE COORDINATED FINISHES.
Layer thicknesses shown are nominal. Illustration not to scale.
S180® VS. 925 STERLING SILVER
Two genuine silver-containing materials, designed for different priorities.
| FEATURE | S180® / TARNISH-RESISTANT SILVER | 925 STERLING SILVER |
|---|---|---|
| Material classification | GONA’s proprietary color-through silver alloy | Standard precious-metal alloy |
| Silver content | ≥20% in gold and rose-gold tones; ≥25% in silver tone | 92.5% silver |
| Core color | Silver, champagne-gold or soft rose-gold | Naturally silver-colored |
| Surface construction | 0.2 μm palladium barrier layer, 0.2 μm coordinated finish and protective coating | Varies by design; may be unplated, rhodium-plated, gold-plated or rose-gold-plated |
| How it ages | Plated luster may soften to reveal a coordinated core color | May develop natural oxidation or a darker patina when exposed |
| Typical GONA use | Used extensively in gold-tone and rose-gold-tone jewelry | Used for most essential bracelets, necklaces and earrings, plus selected antiqued charms |
| Primary design value | Color continuity, skin-friendly wear and resistance to visible dark tarnish | High silver content, traditional sterling value and the ability to create intentional oxidized detail |
Neither material is universally better. GONA selects each one according to the color, construction, intended wear and creative purpose of the design.
OUR CURRENT SILVER CONTENT STANDARD
GOLD & ROSE-GOLD-TONE S180®
MINIMUM 20% SILVER
Latest SGS-tested average:
21.2%
SILVER-TONE S180®
MINIMUM 25% SILVER
Latest SGS-tested average:
27.2%
GONA’s current minimum standards are higher than the original S180 formulation. Monthly SGS sampling monitors newly produced jewelry against these targets. The percentages below refer to real silver blended throughout the alloy core, not to a surface coating or plated finish.
WHY IS IT CALLED S180®?
The S180 name comes from the original formulation, which contained approximately 18% silver — or 180 parts per thousand. As the material evolved, GONA increased the minimum silver content. S180® remains GONA's registered trademark for this color-through silver alloy family.
WHY WE DEVELOPED S180®
We developed S180 to address two recurring concerns in plated jewelry: visible darkening as a plated silver-colored core becomes exposed, and the irritation or green skin discoloration sometimes associated with low-cost base-metal jewelry.
Our answer was a silver-rich, color-through alloy made with selected precious metals and other carefully chosen alloying elements. The core itself carries the intended silver, champagne-gold or soft rose-gold tone and is designed for skin-friendly, hypoallergenic wear.
We then paired each core with a 0.2 μm coordinated plated finish, a 0.2 μm palladium barrier layer and a protective coating — thicker than the approximately 0.03 μm flash plating common in mass-market jewelry.
The result is a dual color-protection system that still allows shaping, hand-setting and everyday wear. Excluding solid 14K gold, more than 70% of GONA's current gold-tone and rose-gold-tone jewelry uses an S180 core.
QUALITY CONTROL, REPEATED EVERY MONTH.
Each month, GONA selects a proportion of newly produced jewelry for independent SGS testing of silver content, plating thickness and regulated metals.
CURRENT S180® SILVER CONTENT
Gold-tone and rose-gold-tone S180: 21.2% average silver by weight
Silver-tone S180: 27.2% average silver by weight
REGULATED METALS
No lead, cadmium or nickel detected within the laboratory reports’ stated detection limits in the submitted samples.
0.21 μm AVERAGE 14K GOLD PLATING
In an SGS test of an S180® ring, the 14K gold-plated finish measured:
Point 1 — 0.20 µm
Point 2 — 0.21 µm
Point 3 — 0.22 µm
Average — 0.21 µm
Report No. SZHL260602861801JW
VIEW FULL TEST REPORTTest results apply to the specific samples and tested locations submitted to SGS. ‘Not detected’ means below the laboratory reports’ stated detection limits. Measurements may vary by product, production batch and test location.
WHAT S180® IS DESIGNED TO DO
- Help preserve a brighter plated finish for longer through a thicker multi-layer surface
- Reduce abrupt color contrast as the plated finish naturally ages
- Resist the charcoal-black tarnish commonly associated with exposed sterling silver
- Support skin-friendly, hypoallergenic wear and reduce unwanted green skin discoloration
WHAT S180® CANNOT DO
- Keep the original high-polish plated luster unchanged forever
- Make any plated finish permanent
- Prevent scratches, friction, impact or surface wear
- Make chlorine, salt water, bleach or strong chemicals harmless to the finish
- Replace appropriate jewelry care
CARE FOR YOUR S180® JEWELRY
S180 is designed for regular wear, including showering, swimming and exercise. Thoughtful care is recommended to preserve the brighter plated luster for longer, but not because the color-through core will turn black.
APPLY PERSONAL-CARE PRODUCTS FIRST
Allow perfume, lotion, hairspray and other personal-care products to dry before putting on your jewelry.
CLEAN IT GENTLY
Use a clean, soft, lint-free cloth. Avoid silver dip, toothpaste, abrasive polishing cloths and harsh jewelry cleaners.
STORE IT SEPARATELY
Store each piece in a dry pouch or lined box to reduce scratching, friction and tangling.
S180® MATERIAL FAQS
What exactly is S180®?
S180® is GONA’s registered family of color-through, silver-containing jewelry alloys, usually identified on our product pages as Tarnish-Resistant Silver.
Is S180® real silver?
Yes. Real silver is blended throughout the alloy core — it is a genuine silver-containing material, not a surface coating.
How much silver is in S180®?
Current minimums are 20% in gold and rose-gold tones and 25% in silver tone. Latest SGS-tested averages are 21.2% and 27.2% respectively.
Is S180® the same as 925 sterling silver?
No. S180 is a distinct proprietary color-through silver alloy. 925 sterling silver contains 92.5% silver and is naturally silver-colored.
How is S180® jewelry finished?
A coordinated multi-layer finish: protective coating, 0.2 μm plated finish (rhodium, 14K gold or rose gold), and a 0.2 μm palladium barrier layer over the color-matched S180 core.
Why is it called S180® if it now contains 20% or more silver?
The name comes from the original formulation of approximately 18% silver (180 parts per thousand). As the material evolved, GONA increased the minimum silver content. S180® remains the registered trademark.
Why does GONA use S180® instead of gold-plated sterling silver?
To reduce visible darkening when a plated silver-colored core becomes exposed, and to keep color continuity with a color-through core.
Does S180® tarnish or turn black?
S180 is designed to resist the charcoal-black tarnish associated with exposed sterling silver. As plating ages, a coordinated core color is revealed instead of a darkened silver core.
Can I shower, swim or exercise while wearing S180® jewelry?
Yes. S180 is designed for regular wear, including showering, swimming and exercise. Rinse and dry after water and activity to preserve the plated luster.
Is S180® hypoallergenic?
S180 is designed for skin-friendly, hypoallergenic wear. Independent testing found no lead, cadmium or nickel within stated detection limits in the submitted samples.
Are all GONA products made with S180®?
No. GONA uses both S180 and 925 sterling silver for different purposes. Most essential bracelets, necklaces and earrings use 925; S180 is used extensively in gold-tone and rose-gold-tone jewelry.
How can I tell whether a GONA product uses S180® or 925 sterling silver?
S180 is identified on product pages as Tarnish-Resistant Silver. 925 sterling silver is identified as Sterling Silver / S925.
What does GONA's monthly SGS testing measure?
Each month GONA selects newly produced jewelry for independent SGS testing of silver content, plating thickness and regulated metals.
How should I care for S180® jewelry?
Rinse after water and activity, apply personal-care products first, clean gently with a soft cloth, and store separately.
Discover jewelry made with color-through S180 cores across silver, 14K gold-tone and rose-gold-tone finishes.
EXPLORE ALL GONA MATERIALS
Learn how GONA selects 925 sterling silver, S180® Tarnish-Resistant Silver, solid 14K gold, gemstones and plated finishes — and how independent testing supports our material standards.