Sterling silver (925)

What it is

92.5 percent silver and 7.5 percent other metal, almost always copper. The jewelry standard for silver; stamped 925. Tarnishes to grey or black in air and polishes back; copper, not nickel, is the alloying metal in most US sterling.

Alloys: Mixtures of metals used because pure gold and silver are too soft to wear; the other metals set the color and the hardness, and sometimes the allergy question.

Wikidata: Alloy of silver containing 92.5% by mass of silver and 7.5% by mass of other metals, usually copper. Q31576 →

In the research

1 PubMed papers mention it with jewelry, allergy, eyewear or UV; the three most recent:

• Tarnish tattoos: localized cutaneous argyria from sterling silver in fresh piercings. A case series · Clinical and experimental dermatology, 2025

A paper is a paper, not a verdict: titles are listed so you can read them, and a study on one fabric or one filter says little about the piece in your hand.