Sterling Silver 925 — Complete Buyer's Guide

By Dmitry Strugovshchikov, founder of STRUGA

Sterling silver 925 is an alloy of 92.5% pure silver and 7.5% copper — the universal silver standard used in jewelry worldwide for over 800 years. It carries a tiny «925» hallmark on a hidden surface, tarnishes naturally with skin contact (silver sulfide forms a microns-thin patina), and is one of the most repairable and durable metals in jewelry. STRUGA works exclusively in 925, with no rhodium plating — a Living Silver philosophy that lets the metal evolve with its wearer. This guide is the complete reference: what 925 is, how to verify it's real, the global hallmark map, sterling vs other metals, care, longevity, and how STRUGA uses it differently from mass-market silver brands.

Updated September 11, 2026 · first published May 9, 2026

- Sterling silver 925 is an alloy of 92.5% pure silver and 7.5% copper — the universal silver jewelry standard, anchored for 800+ years in Europe.

- Pure silver (.999 fine) is too soft for daily wear; the 7.5% copper hardens 925 to hold detail and survive use without changing its silvery colour.

- Key numbers: density 10.36 g/cm³ for sterling against 10.49 for pure silver, fully liquid at 893 °C against 961.78 °C, hardness 75 HV annealed against 30 HV, 0% nickel, and about $2 per gram of raw silver at the 20–21 August 2026 quote.

- Verify real 925 by seven checks, from kitchen to laboratory: at home you have the «925» hallmark, the magnet test (silver is non-magnetic), a density check, an ice cube and a white polishing cloth; nitric acid and the XRF scan belong to a jeweller, and only XRF closes the question — weight alone proves nothing.

- STRUGA works exclusively in 925 with no rhodium plating — a Living Silver philosophy where the metal stays exposed and develops patina; oxidation is a separate deliberate finishing step, not the same thing.

- 925 is the base of every STRUGA piece across 11 design families in CODEX, RITUAL, LAB, DARK UNION and ISLAND ARTIFACTS, combined with Graphite carbon fiber or Seymchan meteorite; Dark Union wedding rings are made in 3–6 weeks.

By Dmitry Strugovshchikov and Ekaterina Strugovshchikova, founders of STRUGA

What is 925 sterling silver?

Sterling silver is an alloy. The number «925» refers to its purity: 92.5% silver, 7.5% other metal — almost always copper. This is the worldwide standard for silver jewelry; «sterling» on a piece from a London jeweler, an American maker, or a Bali workshop means the same thing. The hallmark «925» means the same thing.

The 92.5%-silver / 7.5%-copper composition that defines this alloy is documented in the standard public reference on sterling silver, and global silver supply data is published by the USGS National Minerals Information Center.

The standard exists because pure silver — 99.9% (.999 fine) — is too soft for daily wear. A pure-silver ring would deform under the pressure of a tight grip; a pure-silver clasp would lose its tension within months. The copper alloy hardens the metal enough to hold detail and survive use, while keeping the colour and chemistry of silver. The copper percentage is small enough not to change the visible tone — a 925 piece looks like silver, not like a copper-colour mix.

The word «sterling» itself comes from medieval England — it appears in 12th-century records to describe a specific silver coinage standard, later codified at 92.5% purity. The name stuck for jewelry. Today, every country that hallmarks silver jewelry uses 925 as the baseline sterling standard.

For broader context on how STRUGA inherits the Bali silver tradition that has worked sterling for over a thousand years, see our Bali silver guide.

925 sterling silver — the verified numbers

Property	Sterling silver 925	Pure silver 999
Composition by weight	92.5% silver, 7.5% copper	99.9% silver
Density	10.36 g/cm³	10.49 g/cm³
Fully liquid at	893 °C	961.78 °C
Hardness, annealed	75 HV	30 HV
Hardness, work-hardened	150 HV	100 HV
Nickel content	0%	0%
Written into law	1275	—

Density is the figure most often quoted wrong: 10.49 g/cm³ belongs to pure silver, and the 925 alloy sits lower at 10.36 g/cm³ because copper is lighter than silver. Hardness is the reason the copper is there at all — annealed sterling reads 75 HV against 30 HV for pure silver, and working the metal takes it to 150 HV. Sterling has no single melting point: it starts to give near 780 °C and is fully liquid at 893 °C. The date 1275 is the statute of Edward I, the first time the standard was written into law.

What the metal inside a piece is worth follows from weight, not from the hallmark. Silver traded between $66.85 and $69.70 per troy ounce on 20–21 August 2026 — about $2 per gram of a finished 925 object. Across 128 STRUGA pieces the median weight is 5.07 g; by type, rings 4.7 g, earrings 3.9 g, necklaces 9.0 g, bracelets 17.0 g, chains 31.0 g, ear cuffs 1.6 g. So the raw silver in the 4.7 g Thorn Ring comes to roughly $9.50, in the 45 g Big Thorn Bracelet to about $90, and in the heaviest object we make — the 95.2 g Carabiner #2 Big Cross Bracelet — to about $190. Everything above that figure is casting, hand finishing, and the hours behind them.

How to check 925 silver at home — seven tests, from kitchen to lab

At home you check a piece with a magnet, an ice cube and a white cloth — three minutes, no reagents; that is enough to rule out plated steel and a crude fake. On a finished piece only an XRF reading at a jeweller settles the question. The seven tests below run in order of access: the kitchen ones first, the jeweller ones last.

Test	Time	Cost	Reliability	Destructive
Hallmark	seconds	free	medium	no
Magnet	5 seconds	minimal	medium	no
Density / weight	minutes	free	medium	no
Ice	1 minute	free	low–medium	no
Polishing cloth	seconds	minimal	medium	no
Acid	minutes	at a jeweler	high	scratch
XRF	seconds	small fee	definitive	no

1. Hallmark. Look for the «925» stamp — sometimes «sterling», sometimes a national mark such as the British lion passant. It is small and sits on a hidden surface: inside a band, the back of a pendant, inside a clasp; a 10× loupe makes it readable. Most jurisdictions require the mark by law for silver sold as sterling, so its absence is the single strongest red flag. Caveat: fake stamps exist, so treat the hallmark as the first filter, not as proof.
2. Magnet. Silver — pure or 925 — is non-magnetic. Hold a strong neodymium magnet against the piece: if it pulls, the core is steel or nickel. The magnet costs next to nothing and the test takes five seconds. Caveat: brass and several other base alloys are non-magnetic too, so the magnet disproves rather than proves.
3. Density and weight. The 925 alloy has a density of about 10.36 g/cm³ (pure silver — 10.49). If you know the volume, weigh the piece: a gap of more than 5% points to another metal. Caveat: weight alone settles nothing — silver-coloured pewter and some nickel alloys weigh close to silver. A heavy piece does not prove silver and a light one does not disprove it; earlier silver-buying guides treated weight as the primary criterion, and that advice is wrong.
4. Ice. Pure silver conducts heat better than any other metal — 429 W/(m·K); the 925 alloy falls slightly below that and still leaves steel an order of magnitude behind. Rest an ice cube on a flat surface of the piece: on silver it starts melting visibly faster than on steel or glass. It works on flat, heavier pieces; a thin ring gives a weak signal. The test points a direction rather than delivering a verdict.
5. Polishing cloth. Rub a hidden spot with a clean white cloth. Real 925 leaves faint grey-black traces on the fabric — that is silver sulfide, the same film that shows as tarnish. Plated steel and nickel alloys leave the cloth clean. Fast, and it damages nothing. Caveat: a freshly polished piece leaves almost no trace.
6. Acid test (at a jeweller, leaves a mark). A tiny scratch and a drop of dilute nitric acid: real 925 gives a creamy white reaction, pure copper turns green, brass turns green-blue, silver-plated steel changes colour at the edges where the plating is worn. The method is destructive, so it is used on a hidden inner surface and usually on scrap or unmarked pieces.
7. XRF analysis (the conclusive test). An assayer scans the piece with an X-ray fluorescence gun in seconds and reports the exact silver percentage — non-destructively, accurate to a fraction of a percent. Available at established jewellers, assay offices and refiners for a small fee. It is the only test that closes the question on a finished piece.

One filter stands apart because it works before the purchase rather than after it: provenance and seller. Auction silver from a reputable dealer, jewelry from a brand with verifiable workshops and decades of trade history, pieces from a maker whose work is documented online — all carry implicit verification.

On every STRUGA piece the 925 hallmark is stamped before final finishing — the same standard international assay law requires; the full process is in our how STRUGA is made guide.

Why is silver alloyed at all? Why exactly 92.5%?

Because pure silver is too soft for daily wear: 7.5% copper gives the metal its working strength without changing its nature. Three answers stack on each other.

1. Hardness. Pure silver is among the softest precious metals — Mohs hardness around 2.5–3, similar to gold. A pure-silver wedding ring would scratch, dent, and lose its shape within years of daily wear. The 7.5% copper raises the alloy's hardness measurably without making it brittle.

2. Workability. Pure silver can be hammered, drawn, and forged, but it's also gummy under tools — it tends to drag and tear during precision finishing. Sterling has more «cut» — a file bites cleanly, a graver carves a sharp edge, a polishing wheel produces a true mirror surface.

3. Why 92.5% specifically? Historical convention more than chemistry. Early sterling standards in medieval Europe varied between 92.5% and 95.8%; the 92.5% version became dominant because it gave the best balance between durability and the silvery colour the market wanted. Modern jewelry has stayed with the standard because the entire global trade — refiners, casting houses, hallmark assayers, retailers — speaks the same numerical language.

Higher-purity alloys exist. .950 (Britannia silver) was a UK standard introduced in the 1690s to combat coin clipping; it's softer than .925 and rare in modern jewelry. .999 (fine silver) is the purest commercially available; used for some bullion-style pendants and chain-mail style jewelry where the soft metal can be tolerated. .800 is a continental European standard with more copper — harder but visibly less «silvery».

STRUGA works exclusively in .925. It's the standard that gives STRUGA hand-finishing the bench behaviour we want and the patina behaviour our wearers expect.

Common silver hallmarks worldwide

Different countries hallmark silver differently. The numerical standard converges at 925 for sterling, but the marks vary.

UK. A lion passant (a walking lion in profile) accompanies the 925 number. Older UK pieces also carry an assay-office mark (London leopard, Birmingham anchor, Sheffield crown, Edinburgh castle) and a date letter showing the year of hallmarking.

USA. The word «sterling» or «925» without a national hallmark — the US has never had a national assay office. Maker's marks are common.

EU. «925» plus a country-specific assay mark. France uses Minerva's head; Germany uses a crescent moon and crown; Italy uses a fascio plus province number.

Mexico. «.925» or «MEX 925», sometimes with the city of manufacture (Taxco being the most common silver town).

Bali / Indonesia. «925» plus often a maker's mark. STRUGA pieces carry the standard 925 stamp, applied at our full-cycle Bali hub. Background on the centuries-old Bali silver tradition in our Bali silver guide.

Thailand. «925» or «Sterling»; Thai-made silver is often hand-assembled chain or fine wirework.

The paperwork behind the number: internationally, recommended fineness grades are set by ISO 9202 (Jewellery and precious metals — Fineness of precious metal alloys). In the UK, the Hallmarking Act 1973 makes it illegal to sell an item described as silver without an approved hallmark, with narrow weight exemptions. Across much of Europe, the 1972 Convention on the Control and Marking of Articles of Precious Metals lets one country's Common Control Mark be recognised in the others. For skin safety, the EU nickel rule (EN 1811) caps nickel release at 0.5 µg/cm² per week — one more reason honest 925, which needs no nickel, stays the default for daily wear.

Silver purity standards compared — 800, 875, 900, 925, 950, 999

Silver appears under multiple purity standards worldwide. The 925 standard dominates jewelry, but knowing the others matters when you encounter older pieces, regional standards, or industrial silver.

Standard	Silver content	Typical use	Common region	Hallmark
800 silver	80.0%	Cutlery, lower-grade decorative	Germany, Italy historical	800
875 silver	87.5%	Soviet-era and Russian jewelry	Russia, USSR archives	875
900 silver (coin)	90.0%	Historical coinage, watchcases	USA pre-1965 coins	900 / coin
925 sterling	92.5%	Modern jewelry standard worldwide	Global — STRUGA, all major brands	925 / sterling
950 silver	95.0%	Mexican silver, French standard	Mexico, France	950 / 1er titre
958 Britannia	95.84%	Higher British standard, art silver	United Kingdom	958 / Britannia figure
999 fine silver	99.9%	Bullion, electrical, very soft for jewelry	Global — bullion only	999 / .999

925 sits at the engineering sweet spot: enough silver to look like silver, enough copper to hold a shape and survive daily wear. STRUGA works exclusively in 925 — the same standard as Tiffany & Co, Chrome Hearts, John Hardy, and every reputable jeweller worldwide.

Is 925 silver the same as sterling silver?

Yes — «925» and «sterling» are two names for one standard: at least 92.5% pure silver by weight. The number is the hallmark, the word is the legal name for the same alloy. In the United States the FTC bars the words «Sterling» or «Ster.» on anything below 925/1000ths pure silver (16 CFR § 23.5). The National Stamping Act allows a tolerance of four parts per thousand, ten where solder is present. A legally stamped sterling piece can therefore assay at 921, not 925. Britannia at 958 and French 950 are higher standards, not other names for sterling. The purity table above places 925 against every silver standard you will meet; the materials that carry the look but not the metal are named further down.

Where the sterling standard comes from

The 92.5% standard is medieval law, not marketing. In 1300, Edward I fixed English silverware to the fineness of the coin alloy and ordered it marked with a leopard's head — the earliest hallmark still in use. The word «sterling» itself is older and its origin is genuinely unsettled: the popular «Easterling» story is considered discredited by the Oxford English Dictionary, which cautiously prefers a derivation from Old English steorra — «star», after the small stars on some early Norman pennies. Between 1697 and 1720 Britain briefly forced a higher standard — Britannia silver at 958 — to stop silversmiths from melting coins; sterling returned in 1720 and Britannia remains a voluntary option. American «coin silver» of the 18th–19th centuries ran at roughly 900, made literally from melted coinage, until sterling 925 displaced it in the late 19th century.

Sterling silver vs other precious metals

How 925 compares to the other metals you might consider for a daily-wear piece — particularly a wedding ring.

14k or 18k gold. Gold is denser, more expensive, and less hard than sterling silver (gold Mohs ~2.5 vs sterling ~3). A 14k gold ring carries roughly 10× the metal cost of an equivalent sterling ring of the same volume. Gold doesn't tarnish; sterling develops Living Silver patina. For couples comfortable with patina (and increasingly many are), sterling delivers similar wear-life at a fraction of the cost.

Platinum. Denser still and hardest of the major precious metals. Doesn't tarnish, doesn't react. Significantly more expensive than gold (typically 1.5–2× gold price per gram). Repairs require specialist equipment because platinum's high melting point makes ordinary jewelry torch work difficult. Sterling silver is repairable by any silversmith with standard tools; platinum often requires shipping back to a specialist.

White gold. Yellow gold alloyed with white metal (palladium, nickel, or other), then usually rhodium-plated to enhance the white colour. The plating wears through and needs re-applying every few years. STRUGA's Living Silver philosophy is the opposite: no plating, the metal stays exposed and evolves. Detailed comparison in our silver patina guide.

Palladium. A platinum-group metal, lighter than platinum, doesn't tarnish, generally hypoallergenic. Less expensive than platinum but more than gold. Used in some wedding rings; less common as a primary jewelry metal. STRUGA doesn't currently work in palladium.

Metal	Price of piece	Hardness (Mohs)	Darkens	Repair
Sterling 925	moderate	~2.5–3	yes, reversible	any jeweler
Gold 585 / 750	≈10× on metal	2.5–3	no	any jeweler
White gold	high	2.5–3	plating wears off	re-plating cycles
Platinum	highest	4–4.5	no	specialist
Palladium	above gold	~4.75	no	specialist

Living Silver — why STRUGA doesn't rhodium-plate

Most commercial silver jewelry is rhodium-plated. A thin layer of rhodium (a member of the platinum group, hard, shiny, inert) is electroplated over the sterling silver. The piece looks bright forever, doesn't patina, doesn't react. Rhodium is also expensive — in 2026 it sells for roughly twice gold per gram — so manufacturers use the thinnest possible plating, which then chips off at edges within a few years, exposing the silver underneath in mottled patches that look noticeably worse than honest patina ever would.

STRUGA doesn't rhodium-plate. The metal is left exposed, alive, responsive to its wearer. We call this Living Silver: 925 without a coating, evolving day by day instead of frozen in time.

Three reasons we made this choice. Honesty — plating hides what the metal actually is. Repair-ability — Living Silver only ever needs polishing or re-oxidation, operations any silversmith can do in minutes. The personal record — a piece that doesn't change is a piece that doesn't remember. After two years of wear, no two STRUGA rings look the same.

Full Living Silver explanation including the chemistry of why the patina forms, how it reads on different forms, year-by-year evolution, and how to reset to bright when desired — in our silver patina guide.

How sterling silver is used at STRUGA

925 is the base material of every STRUGA piece. From there it stays pure or combines with one of three other materials.

Pure 925 sterling. Most of CODEX, classic Blade bands, Signature Heart work, basic Signature Asymmetric. Either bright (designed to develop natural patina) or pre-oxidised (intentionally darkened with liver of sulfur — a controlled process explained in our patina guide).

925 + carbon fiber. A forged carbon panel set into a precision-cut channel in the silver. The carbon comes in our six-tone Graphite palette: Classic, Bloody (wine-red), Arctic (smoky white), Winter (cold grey-blue), Multy Graphite (iridescent), Toxic (acid-green vein). Most carbon pieces live in RITUAL and the dedicated Carbon family. Pure-carbon pieces (without silver, on suede cord) sit in LAB. Material details in our carbon fiber and meteorite jewelry guide.

925 + Seymchan meteorite. A thin acid-etched slice of pallasite meteorite found in Kolyma in 1967, set by hand into a cold-closed silver bezel. The Widmanstätten pattern (an iron-nickel crystal lattice grown in deep space) makes every slice unique. Most Seymchan pieces sit in LAB and Blade. Meteorite collection.

925 + raw stones. Black tourmaline (schorl) in the Thorn / E-0528 amulet model; aquamarine, heliodor and natural quartz in the Classic / E-0530 model and RITUAL. Stones set in their natural geometry, not faceted.

Does 925 sterling silver tarnish?

Yes — and it is reversible. Sterling darkens as the surface reacts with sulfur compounds in air and on skin: a micron-thin film of silver sulfide, not rust and not damage. Brightness comes back in minutes with a soft cloth, and the metal underneath never weakens. STRUGA treats this chemistry as the material's behaviour — Living Silver — not as a defect.

Care, maintenance, longevity

Sterling silver is one of the most forgiving metals in jewelry. It doesn't corrode, doesn't weaken from tarnish (tarnish is purely a surface reaction microns thick), doesn't degrade with normal wear. The five practical rules for daily-wear sterling.

1. Take it off for chlorine. Pool water and hot tubs strip oxidation faster than anything else and accelerate copper-component reactions in the alloy. Salt water is fine; soap-and-water shower is fine; chlorinated pool water is not.

2. Take it off at the gym for heavy lifting. Not for hygiene — silver is naturally antimicrobial — but to protect the piece from impact deformation. A wide silver band can flatten slightly under heavy barbell load.

3. Clean with a soft cloth. A microfibre cloth is enough. Avoid commercial silver polish on intentionally oxidised pieces — it strips the dark finish from the recesses where it was deliberately put.

4. Store separately. Don't drop sterling rings into a tray with other rings. Silver scratches against silver. A small fabric pouch is enough; the original STRUGA box works.

5. Re-oxidise (or send for restoration) when you want. Whenever the patina has gone further than you'd like, send the piece to STRUGA (our Bali hub) or have any silversmith re-oxidise it locally with liver of sulfur. Free for life on every Dark Union wedding ring; small handling fee for other pieces.

Full care protocol including patina chemistry and year-by-year evolution in our silver patina guide.

Sterling silver wedding rings

Sterling silver is durable enough for a wedding ring. It's harder than gold, has been used in wedding bands for centuries, and has the practical advantage of being repairable and resizable by any silversmith.

STRUGA makes wedding rings through Dark Union — a paired-design service where the rings are designed as a conversation between two pieces, sized individually for each partner, finished by hand in our Bali hub. Lead time 3–6 weeks. Lifetime free re-oxidation included.

Common configurations: pure 925 sterling pair ($300–$600), silver pair with carbon-fiber Graphite inlay ($600–$1,400), silver pair with Seymchan meteorite inlay ($1,400–$2,500). Full breakdown of styles, materials, the Dark Union process, and what to expect over five years of wear — in our dark wedding rings guide.

For couples not looking for paired wedding bands but for a single bespoke piece (engagement ring, anniversary piece, custom amulet), use Custom Order instead. Same workshop, same materials, same Living Silver philosophy.

What real 925 should cost

The metal is cheap next to gold or platinum: the raw silver in a 5-gram ring costs less than a coffee. So the price of a finished piece is almost all craft, not metal. Rough bands for 2026: $15–50 for mass-produced unbranded sterling; $50–200 for mid-market chain retail; $150–600 for small-workshop handmade silver, where most STRUGA pieces in the CODEX and RITUAL worlds sit; $600–2,500+ for author-design statement pieces with complex setting or rare inlay like Seymchan meteorite or carbon. The math is a fast honesty check. If a 30-gram "handmade artist 925" ring is $25, something is wrong — it is plated, the silver is below 925, or no one actually paid the maker.

Before you buy 925 — a seven-point check

1. Find the hallmark (925 / sterling) on a hidden surface — and remember its absence is a warning, not a verdict.
2. Run a strong magnet over the body of the piece, not just the clasp.
3. Weigh it in the hand: suspiciously light for its size means plated or hollow base metal.
4. Check the colour: warm white with soft lustre, not chrome-bright, not grey.
5. Ask the seller what exactly the alloy is — «silver-plated», «silver tone» and «nickel silver» are answers, and they all mean no.
6. For a serious purchase, ask for an XRF test — any decent jeweller offers it.
7. Buy from a maker who states the alloy, the finish and the care rules in writing.

What 925 is not — the look-alikes to watch

Several materials look like silver and get sold as it, but carry little or none. Worth knowing by name:

• Nickel silver / German silver / alpaca — copper-nickel-zinc alloys with zero actual silver, despite the names.
• Tibetan silver — usually a low-grade alloy; some pieces sit under 30% silver and almost never carry a 925 stamp.
• Mexican silver below sterling — sometimes stamped 800 or 900. Real silver, just not sterling; read the number, not the word.
• Silver-plated — a thin silver skin over base metal that wears through in months. Look for "plated" or "SP", or the missing 925 mark.

A few more stamps that are not sterling: EPNS (electroplated nickel silver — plated base metal), «Silver tone» (the colour, no silver at all), a lone «Ster» on cheap imports (often plated), and «925 Italy» on steel-weight pieces — Italian sterling is real, but the stamp is widely forged, so verify the metal, not the geography. Two honest quirks worth knowing: some genuine vintage pieces carry old regional stamps of 800, 900 or 950 instead of 925 — lower or higher standards, not fakes; and clasps or springs on real sterling chains are sometimes steel for strength, so a magnet grabbing the clasp alone proves nothing.

Where STRUGA sterling fits in the dark silver landscape

The brands that take dark silver seriously — Chrome Hearts, Parts of Four, Werkstatt:München, Bill Wall Leather, Gaboratory, Lone Ones, The Great Frog — almost all work in 925 sterling. The differentiation among them is design language, materials beyond silver, and finishing philosophy. STRUGA's specific position: 925 base, no rhodium plating (Living Silver), unique materials (Seymchan meteorite + Graphite carbon palette) that no other brand on the comparison list runs simultaneously, and a price-to-craftsmanship ratio that opens up serious dark silver to buyers who would otherwise be priced out of Chrome Hearts territory. Full landscape in our brands like Chrome Hearts guide.

925 sterling silver — the numbers that matter

Specific figures buyers, valuers, and writers reference most often:

The figures live in the table near the top of this guide. What they mean inside an object depends on its weight, and every STRUGA weight is published on the object's own page:

• Thorn Ring — 4.7 g, the median STRUGA ring.
• Big Thorn Bracelet — 45 g.
• Blade Big Links Bracelet — 85 g.
• Carabiner #2 Big Cross Bracelet — 95.2 g, the heaviest object in the catalog.

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Continue from STRUGA catalog:

• Browse 925 silver catalog →
• Featured piece in this category →

Sources and further reading

• Silver — Encyclopedia Britannica
• GIA — Silver in jewelry

Further reading from STRUGA Journal

• Oxidized silver — what it is and how to care for it
• Sterling silver vs gold, white gold, and platinum