Sterling silver 925 earrings: what to know

Q: What does 925 mean on earrings?

Silver 925, or sterling silver, contains 92.5% pure silver and 7.5% other metals, most often copper. Pure silver at 99.9% is too soft to hold a jewellery shape, hence the alloy. In France, 925 parts per thousand is the most common fineness for pieces sold as silver.

Q: Why do my silver earrings turn black?

That darkening is tarnishing: silver reacts with sulphur compounds present in air, perspiration, cosmetics and household products. It is not a sign of poor quality or fake silver, and the layer comes off with a suitable polishing cloth.

Q: Is sterling silver suitable for sensitive skin?

In most cases yes, but the remaining 7.5% matters. A copper alloy is generally well tolerated, while an alloy containing nickel can trigger a reaction. The European REACH regulation caps nickel release from jewellery in prolonged skin contact, and items inserted into a pierced ear fall under the strictest limit.

In short:
Silver 925 means 92.5% pure silver, the rest being an alloy meant to harden the metal, most often copper.
Tarnishing is a normal, reversible reaction, not a sign of fake silver.
The hallmark is the only physical proof: without a 925 stamp or a guarantee hallmark, nothing confirms the stated fineness.
For sensitive skin the point of attention is not silver itself but the 7.5% alloy, nickel in particular.

What the number 925 actually means

Pure silver, known as fine silver, is 999 parts per thousand. It is too malleable for a piece worn daily: a stud post would bend, a hoop would lose its shape. The industry therefore alloys it with other metals.

Sterling silver 925 is the standard alloy: 92.5% pure silver, 7.5% other metals. Copper is the most common addition.

Recognising real sterling silver

Three things can be checked before buying:

The 925 stamp engraved on the post, the clasp or the ring.
The guarantee hallmark, mandatory in France above a certain weight threshold.
The stated fineness on the product page, which commits the seller.

Tarnishing is not a defect

Silver reacts with sulphur compounds in the air and in perspiration. The grey or black layer that appears is a surface chemical reaction, not wear of the metal.

What speeds it up:

perfumes and hairspray sprayed onto the piece,
chlorinated household products,
open-air storage rather than a closed pouch,
heavy perspiration.

A polishing cloth impregnated with anti-tarnish product removes the layer in a few passes. Silver dips work but are harsh on stones and plated parts.

Sensitive skin: look at the alloy, not the fineness

The 7.5% alloy	Skin tolerance	Note
Copper	Generally good	Most widespread alloy
Nickel	At risk	Capped by REACH
Argentium (germanium)	Good	Less prone to tarnishing, more expensive

A reaction after a few hours of wear, with redness and itching at the contact point, points to contact allergy. A dermatologist settles the question, an article cannot.

Frequently asked questions

What does 925 mean on earrings?

Silver 925 contains 92.5% pure silver and 7.5% other metals. Pure silver is too soft to hold a jewellery shape.

Why do my silver earrings turn black?

Tarnishing from contact with air, perspiration or cosmetics. The layer comes off with a suitable polishing cloth.

Is sterling silver suitable for sensitive skin?

In most cases yes. The point of attention is the 7.5% alloy, nickel in particular, whose release is capped by REACH.