What is sterling silver?

Sterling silver is an alloy containing 92.5% pure silver and 7.5% other metals, usually copper. It is stamped with the hallmark 925. Fine silver (999) is 99.9% pure but too soft for most jewellery.

Why does silver tarnish?

Silver tarnishes when it reacts with sulfur compounds in the air, forming silver sulfide — a dark, dull layer on the surface. The copper in sterling silver accelerates this. Regular cleaning and proper storage slow tarnishing.

What is the difference between 925 and 999 silver?

999 silver (fine silver) is 99.9% pure silver — very soft and bright white, used in bullion coins and bars. 925 silver (sterling) contains 92.5% silver alloyed with copper for hardness, making it practical for jewellery and cutlery.

Is silver a good investment?

Silver is a recognised store of value and is more affordable than gold. It has industrial uses (electronics, solar panels) that support demand. However, it is more volatile than gold. Most investors buy silver coins, bars, or ETFs rather than jewellery, which carries a premium.

What Does 925 Mean on Silver? – Purity Grades & Hallmarks Explained

Volume visualization — silver vs. copper

Each droplet = same volume. Silver (10.5 g/cm³) is slightly denser than copper (8.96 g/cm³), so copper takes a little more space for the same weight.

999 Fine

958 Britannia

925 Sterling

900 Coin

830 Nordic

Pure silver (Ag)

Copper (Cu) — by volume

Silver purity at a glance

Each bar shows how much is pure silver (bright) vs. other metals (dark)

99.9%

999

Fine

95.8%

958

Britannia

Most common

7.5%

92.5%

925

Sterling

17.0%

83.0%

830

Continental

10.0%

90.0%

900

Coin

Pure Silver

Other metals (copper, nickel…)

Every silver grade explained

Fine Silver

Hallmark: 999

Silver purity 99.9%

Other metals: 0.1%

Used for: Bullion bars, coins, high-end silverware

📍 Worldwide

✓ Purest, brightest white, hypoallergenic

✗ Too soft for most jewelry, dents easily

Britannia Silver

Hallmark: 958

Silver purity 95.8%

Other metals: 4.2%

Used for: British hallmarked silverware, coins

📍 UK, historically

✓ Very pure, prestigious British standard

✗ Rare, mostly for silverware not jewelry

Most common worldwide

Sterling Silver

Hallmark: 925

Silver purity 92.5%

Other metals: 7.5%

Used for: Rings, necklaces, bracelets, cutlery

📍 Worldwide

✓ The global standard — great balance of purity and durability

✗ Tarnishes over time, can cause reactions if nickel is used

Continental Silver

Hallmark: 830

Silver purity 83.0%

Other metals: 17.0%

Used for: Older Scandinavian silverware, antiques

📍 Norway, Sweden, Denmark (historically)

✓ Harder and more durable

✗ Less pure, not commonly used today

Coin Silver

Hallmark: 900

Silver purity 90.0%

Other metals: 10.0%

Used for: Old US coins, antique jewelry

📍 USA (historically)

✓ Historically significant, durable

✗ Rarely used in modern jewelry

Why does sterling silver turn black?

⚗️

It's the copper

Pure silver (999) barely tarnishes. But the 7.5% copper in sterling silver reacts with sulfur compounds in the air and on skin — forming silver sulfide, which is the black coating you see.

💨

What accelerates it

Humidity, perfume, chlorine (pools), sweat, rubber bands, and wool all speed up tarnishing. Storing silver in airtight bags slows it significantly.

✨

How to remove it

Baking soda + aluminum foil + hot water (electrochemical reaction), silver polishing cloth, or commercial silver polish all work well. The tarnish is surface-only — the silver underneath is fine.

925 vs 958 — direct comparison

Property

Sterling Silver — 925

Britannia Silver — 958

Silver content

92.5%

95.8%

Other metals

7.5% (usually copper)

4.2% (usually copper)

Hardness

✓ Harder, more scratch-resistant

✗ Softer, dents more easily

Tarnish resistance

Moderate

Slightly better (less copper)

Availability

✓ Widely available worldwide

✗ Rare — mainly UK silverware

Price

More affordable

Slightly more expensive

Best for

All jewelry — rings, chains, earrings

Silverware, antique items, UK hallmarked pieces

Stamp

925 or "Sterling"

958 or Britannia mark

Bottom line: 925 sterling is the global standard for a reason — it's the sweet spot between purity and durability. 958 is purer but too soft for most jewelry.

Volume visualization — silver vs. copper

Each droplet = same volume. Silver (10.5 g/cm³) is slightly denser than copper (8.96 g/cm³), so copper takes a little more space for the same weight.

999 Fine

958 Britannia

925 Sterling

900 Coin

830 Nordic

Pure silver (Ag)

Related guides

Karat Guide

14K vs 18K vs 24K explained

White Gold

Alloys, rhodium & cost

Rose Gold

Copper ratio & karats