Oxidised and blackened silver: clean it, do not polish it

An oxidised piece arrives dark, and sooner or later somebody decides it looks dirty. They reach for the polishing cloth that came with a watch, or the jar of silver dip under the sink, and thirty seconds later the piece is bright, shallow and wrong. The finish is not coming back. The problem is that every product sold for cleaning silver is designed to remove exactly the thing an oxidised piece is made of, and none of the packaging mentions it.

Oxidised silver is tarnish that somebody applied on purpose

The dark surface on a blackened silver piece is silver sulfide, the same compound that forms by accident on a neglected teapot. The difference is that a maker applies it deliberately, usually with liver of sulfur, which is a potassium sulfide solution, and controls where it ends up. The piece is dipped or painted, then the high points are brought back by hand so that the recessed detail stays dark and the raised surfaces catch light.

That layer is thin. Not thin like a coat of paint, thin like a few microns, which is thinner than a sheet of paper split a dozen times. It has no body to it. Anything that abrades the surface at all takes a measurable fraction of it away, and nothing you do at home replaces it.

Blackened alloy and black plated pieces are a separate case with the same conclusion. Black rhodium, black ruthenium and gunmetal coatings are deposited layers, often under a micron, and a lacquer finish over the top of an oxidised surface is thinner still. Polishing removes those too, faster.

The four things that will strip it

Impregnated polishing cloths. The yellow inner cloth in a two part polishing cloth carries a fine abrasive and a tarnish remover. That is its entire job. It will lift an oxidised finish on the first pass, and it works fastest on exactly the raised areas where the contrast is supposed to live.

Silver dip. These are usually thiourea in an acid solution, and they dissolve silver sulfide chemically rather than mechanically. On a bright piece they are brutally effective. On an oxidised piece they are total: in under a minute you have a uniformly pale object with no depth in the detail at all.

Abrasive pastes and the foil trick. Bicarbonate of soda paste and toothpaste are both abrasives, and toothpaste is engineered to abrade, which is the point of it. Silver is soft enough that a soft toothbrush and toothpaste will scour a patina off a pendant in a couple of minutes. The aluminium foil, hot water and bicarbonate of soda method is cleverer and just as final: it sets up a small electrochemical cell that reverses the sulfide reaction and pulls the sulfur back off the silver, and it does not know the difference between tarnish you hate and patina you paid for.

The method that is actually safe

Lukewarm water and a single drop of plain washing up liquid in a bowl. No soaking for hours, two or three minutes is plenty. Work crevices with a soft toothbrush or a makeup brush using no pressure at all, the aim being to float dirt out of recesses rather than scrub it off surfaces. Rinse in clean lukewarm water.

Dry immediately and completely. Pat with a soft lint free cloth, then leave the piece somewhere airy for an hour before it goes back in a box, because trapped water in a hollow bead, a bale or a clasp spring will do more harm than the dirt did. Pieces with a lot of enclosed detail, like Heart and Bird Skull Earrings or any open pierced work, hold water in places you cannot see.

Skip the ultrasonic cleaner. It is excellent at loosening things, which includes set stones, glued components and any coating that is already slightly compromised. A jeweller may well use one on a piece they made and can repair. On an unknown piece with an applied finish it is a gamble with no upside.

What normal wear looks like, and why not to fix it

An oxidised piece worn regularly will go bright on the high points first: the outer edge of a ring band, the top of a raised wing, the shoulders of a pendant where it sits against fabric. That is the finish doing what it was designed to do, and it is the reason antiqued work looks better after a year than it does new.

Where it goes wrong is unevenly. A ring that only ever rubs on one side ends up lopsided, and the back of a pendant can polish itself completely smooth against a jumper. Rotating a ring on the finger occasionally, or simply wearing more than one piece, spreads it out.

If the darkness has gone entirely and you want it back, that is a jeweller's job with liver of sulfur, and it is cheap work if there is a bench jeweller near you. Home oxidising kits exist, smell strongly of rotten eggs, need ventilation and a bit of practice, and are not a sensible first experiment on a piece you care about.

What to keep away from it in the first place

Most finish damage is contact damage rather than cleaning damage. Perfume and hairspray are the usual culprits, because they are sprayed in a cloud and land on everything within half a metre. The rule is last on, first off: jewellery goes on after scent, cream and hair products, and comes off before they go anywhere near you.

Chlorinated water is worse than any of them. Chlorine attacks silver alloys directly and will dull and pit a surface in a single long swim or a hot tub session, so pieces come off before a pool. Salt water and sweat are milder but persistent, and sun cream is a thick deposit that sets in recesses.

Alcohol hand gel is the modern one. It evaporates fast enough to be harmless on bare metal but it will haze a lacquered finish, which is what is on a lot of inexpensive blackened work. Take rings off before you use it, or at least wipe them after.

Dark pieces in our own stock, and what we tell people

A good proportion of what we sell is darkened on purpose, including pieces like the Spiderweb Pendant where the whole design depends on light sitting in the raised lines and shadow sitting in the recesses. On that kind of work, cleaning advice and polishing advice are opposites.

We do not know how every supplier achieved every finish, and we will not pretend we do. If you are about to clean something and you want to know whether it is oxidised silver, a black plating or a lacquer over the top, email us with the piece and we will go and read what we have for it.

Our returns policy covers damage in transit and anything sent wrong, and it does not cover a finish that has been polished off. That is not us being difficult, it is that there is no way to put it back without redoing the piece.

Questions people actually ask

Can you polish oxidised silver?

Not without removing the finish. The dark layer is silver sulfide only a few microns thick, and polishing cloths and silver dips are designed specifically to remove silver sulfide. Clean it with lukewarm water and a drop of washing up liquid instead, with no abrasive of any kind.

How do I clean blackened silver jewellery at home?

Lukewarm water with one drop of plain washing up liquid, two or three minutes, and a soft brush used with no pressure to float dirt out of crevices. Rinse in clean water, pat dry with a soft cloth, then leave it to air for an hour so no water stays trapped in a bale or clasp.

Will the black coating wear off my jewellery?

On the high points, yes, and on an oxidised piece that is intended. The raised surfaces brighten with wear while the recessed detail stays dark, which is what gives antiqued work its depth. A jeweller can re oxidise a piece with liver of sulfur if the darkness disappears completely.