What 925 means
The stamp 925 says that 92.5 percent of the metal by weight is silver and 7.5 percent is something else, nearly always copper. Pure silver, stamped 999, is beautiful and very soft; the copper makes an alloy that holds a shape, takes a polish and survives daily wear. That alloy is sterling silver, and it has been the standard for silverware and jewellery for centuries. Other marks you may meet are 900 (coin silver) and 800 (common in older European pieces), both with less silver and more copper.
Why silver goes dark
Silver does not rust. What it does is tarnish: the surface reacts with sulphur compounds in the air, in sweat, in cosmetics, in wool and in some foods (eggs, onions) to form a thin layer of silver sulphide. First the piece looks yellowish, then brown, then grey-black. It is only a film on the surface; the metal underneath is untouched, and the film comes off.
Humidity, pollution and a closed drawer that traps sulphur from rubber or felt all speed it up. Wearing silver slows it down, because the gentle friction of daily wear keeps polishing it.
Rhodium plating
Much modern silver jewellery is finished with a very thin layer of rhodium, a bright white metal from the platinum family. It does not tarnish, so a rhodium-plated piece stays bright for years without polishing. The layer is thin and wears off slowly at the high points (the inside of a ring, the clasp of a chain); when it does, the silver underneath simply behaves like silver again, and a jeweller can re-plate it if you want.
Cleaning at home
- Light tarnish: rub with a silver polishing cloth (a soft cloth impregnated with a mild polish). Thirty seconds brings back the shine. Do not wash the cloth.
- Dirty or greasy pieces: warm water, a drop of mild dish soap, a soft toothbrush for the crevices, rinse, and dry completely with a soft cloth. Never leave silver to air-dry; water spots dull it.
- Heavy tarnish: a liquid silver dip works in seconds but is harsh; use it sparingly, keep it off stones and pearls, and rinse well. For pieces with an intentionally darkened (oxidised) finish, skip dips entirely, because they strip the dark recesses that are part of the design.
What to avoid: toothpaste and baking soda pastes (abrasive, they scratch), bleach and chlorine (they attack the alloy), ultrasonic cleaners for anything with glued or soft stones, and perfume or hairspray sprayed on while wearing the piece.
Storing it
Store silver clean, dry and separately, in a small zip bag, a lined box or an anti-tarnish pouch; a strip of anti-tarnish paper in the box helps. Pieces you wear every day need little more than a rinse and a wipe now and then.
Every silver piece at DiOro999.9 lists its purity and weight. If a listing says rhodium-plated, that is the finish described above; if it says oxidised, it was darkened on purpose and needs the gentler routine.