Silver Alloy Comparison Chart — Sterling, Britannia, Argentium, Coin, Fine
A single-page reference for the five silver alloys you will meet in jewelry and silversmithing: Sterling 925, Coin 900, Britannia 958, Argentium, and Fine Silver 999. Hardness, melting points, tarnish behavior, typical hallmarks, and primary uses — side by side.
At-a-glance reference table
| Alloy | Composition | Hardness (Vickers) | Mohs | Melting point | Tarnish resistance | Typical hallmark | Primary uses |
|---|---|---|---|---|---|---|---|
|
Sterling Silver 925 |
92.5% Ag + 7.5% Cu (typical) | 70–75 | 2.5–3.0 | 893 °C 1640 °F |
Moderate — tarnishes over weeks of air exposure | 925 · lion passant (UK) · sterling · ster | Majority of silver jewelry worldwide; flatware; holloware |
|
Coin Silver 900 |
90% Ag + 10% Cu (historic US coin alloy) | 80–90 | 2.5–3.0 | 890 °C 1634 °F |
Higher than sterling — more copper content | 900 · COIN · historical US marks vary | 19th-century US flatware and jewelry; melted-coin work; contemporary revival pieces |
|
Britannia Silver 958 |
95.84% Ag + 4.16% Cu | 55–65 | 2.5 | 960 °C 1760 °F |
Lower than sterling (less copper) | 958 · Britannia figure (UK) · historically mandated 1697–1720 | Premium UK silversmithing; presentation pieces; raising and chasing work |
|
Argentium Silver 935 / 960 |
Ag + Cu + Ge (germanium) — ≥93.5% or 96.0% Ag | 80–90 (age-hardened) | 2.5–3.0 | 1035 °C (935) / 1055 °C (960) 1895 °F / 1931 °F |
Very low — germanium oxide layer resists tarnish | Argentium ® · 935 / 960 · Flying Unicorn stamp (authorized) | Contemporary studio jewelry; fusing and granulation; laser welding |
|
Fine Silver 999 |
≥99.9% Ag | 25–30 | 2.5 | 961.78 °C 1763 °F |
Very low in clean air; darkens quickly with sulfur exposure | 999 · .999 FS · fine silver | PMC / Art Clay; bezel wire (for fine bezels); bullion bars; plating feedstock |
Composition, hardness and melting data cross-referenced from ASM Metals Handbook, UK Assay Office technical sheets, Argentium International published data, and Rio Grande jeweler-supply alloy tables.
Strengths & trade-offs per alloy
Sterling Silver 925
Strengths — Durable, widely hallmarked, easy to cast and solder
Trade-offs — Tarnishes; copper in alloy can cause firescale during soldering
Coin Silver 900
Strengths — Harder than sterling; historically significant
Trade-offs — Tarnishes faster; less standardized worldwide
Britannia Silver 958
Strengths — Whiter color, less firescale, easier to work for hand-raising
Trade-offs — Softer than sterling; higher material cost
Argentium Silver 935 / 960
Strengths — Firescale-free, fuses without solder, age-hardenable to Vickers 140+
Trade-offs — Higher cost, requires technique adjustment (avoid alumina pickle)
Fine Silver 999
Strengths — Easy to form; hypoallergenic; takes patina cleanly
Trade-offs — Very soft — not suited for ring shanks, prong settings, or stone bezels under wear
Compare two alloys side by side
Pick any two alloys to see their spec cards next to each other. Useful when choosing stock for a specific piece.
Background & FAQ
Why does sterling tarnish but fine silver barely does?
Pure silver is slow to tarnish in clean air. The tarnish you see on sterling is mostly silver sulfide (Ag₂S) forming where sulfur is present — but the copper in the 7.5% balance also oxidizes, producing darker, more uneven patinas than fine silver would on its own. Argentium replaces part of the copper with germanium; germanium forms an invisible oxide layer on the surface that dramatically slows both copper and silver tarnish.
Is Britannia silver "better" than sterling?
Not in a consumer sense. Britannia has more silver (95.84% vs 92.5%), so it is whiter and less prone to firescale, but it is also softer and more expensive. It was mandated in Britain from 1697–1720 to stop silversmiths from melting down coins. Today it is chosen for high-end hand-raised holloware, not for everyday wear pieces.
Why is fine silver not used for ring shanks?
Mohs 2.5 and Vickers ≈25 make it too soft for the daily abrasion a ring sees. Fine silver is excellent for bezels (where it must bend over a stone), metal-clay sintered pieces, and bullion — but ring shanks, prong settings, and bracelet clasps are almost always made in sterling, Argentium, or a higher-hardness specialty alloy.
What does "Coin Silver" mean today?
Historically, US silversmiths melted down US coins (which were 90% silver until 1964) to produce flatware stamped COIN. The alloy composition was 900/1000 = 90% Ag + 10% Cu. Today the term persists for that 90% alloy, though most Coin-marked pieces you encounter are antique.