Silver Purity Marks

What 999, 925, 835 and 800 mean on a piece of silver, and what each number does to hardness, tarnish and the way a ring wears.

A fineness mark states parts per thousand of pure silver. Sterling is 925 — 92.5% silver with 7.5% copper — and that 7.5% is the whole reason a sterling ring survives daily wear instead of bending.

Fine silver 999 is 99.9% pure. It takes marks from everyday objects quickly, which makes it the wrong choice for a band that has to keep its roundness and the right choice for beads, chain and decorative elements where form does the work.

835 and 800 are older continental European alloys: 83.5% and 80% silver, harder pieces, and on 800 the higher alloying content can give the metal a slightly yellowish cast when it sits beside sterling.

Read the number as content rather than as rank. The 925 stamp tells you the piece is the wearable standard; the 800 stamp tells you it resists deformation better at the cost of some softness in the finish.

Tarnish behaves the same way across the range: silver sulfide forms on the surface, pieces worn often lose it as fast as they gain it, and storage in an airtight bag with an anti-tarnish strip slows the rest.

• 999 — fine silver: very soft, used for beads and chain.
• 925 — sterling: the wearable standard for rings and most jewellery.
• 835 — 83.5% silver: harder, common on older continental pieces.
• 800 — 80% silver: hardest of the common alloys, slight yellow cast.

Further reading

• How a Silver Ring Is Made
• Caring for Silver Jewellery