Why brass jewelry darkens and what the metal gives in return

A brass piece will darken, without exception, and the first places to show it are the bracelet clasp and the inside of a ring. A seller finds it easier to say nothing, because any talk of the alloy’s drawbacks turns easily into talk of not buying at all. But a woman who discovers the tarnish six months later, from her own experience, feels cheated, and that costs more than one lost sale. The darkening, the green mark on the skin and the dislike of water all come from one thing: the composition of the alloy.

Copper, zinc and time

Brass is an alloy of copper and zinc, and copper is responsible for every one of its troubles. It combines with oxygen from the air, while moisture and the sulphur compounds of city air speed the reaction up several times over. First the mirror shine gives way to a warm matte, then a brownish tone appears, and regular contact with water brings up a greenish film. This is the same patina that covers bronze monuments in parks. On a monument that film looks noble, while on a bracelet clasp it reads as plain dirt.

The timing varies enormously, and it depends not on the quality of the alloy but on the habits of the woman wearing it. A ring that lives on a bathroom shelf and goes on over damp hands dulls within a month. The same ring, wiped with flannel after wear and kept in a closed box, holds its color for a year and longer. Sweat, creams, perfume and sea salt all speed things along.

Some workshops coat brass with a protective lacquer, and it pushes the tarnish back by a year or two. The lacquer wears through first on edges, on facets and wherever the metal rubs against fabric, and renewing it is a job for a jeweler. After that, the whole thing starts over.

The picture comes out gloomy, so it needs a correction. Brass does not rust at all, because there is no iron in the alloy and rust-colored pitting has nowhere to come from. The oxide sits right on the surface and comes off in five minutes, so this is maintenance, like cleaning suede boots, not damage.

The green line and water

The second drawback frightens people more than the first, though it does noticeably less harm. The salts and acids in sweat react with the copper, the products stay on the skin, and a green line appears under the ring. Soap and water remove it. This is not an allergy: skin reacts to nickel, and ordinary brass has none, so nickel turns up only in special grades like nickel brasses.

The line shows up differently on different people, and there is no predicting it in advance. On one woman it appears the first hot day she spends walking, on another it never appears in years of wear. It comes down to the acidity of the sweat, the cream under the bracelet, the heat outside and how tightly the metal sits. The remedies are boring and they almost always work. Put cream on half an hour before the jewelry, keep a wide bracelet loose in the heat, and wipe its inside in the evening. If you already know you are sensitive to metals, wear the piece around the house for a couple of hours and look at your skin.

Water is stricter than sweat. Brass does not go into the shower, the pool or the sauna, and you do not wash dishes in it either. Chlorinated water ruins the surface in a few swims, sea salt works more slowly but more surely, and steam-room heat multiplies the oxidation. The surest way to reduce a brass piece to a sorry state is to wear it without ever taking it off.

What makes brass worth the trouble

Brass is malleable, and that is its great virtue. It casts, holds fine relief, solders, polishes to a mirror and takes a matte finish. Almost anything drawn on paper can be made by hand. A link that has opened up or a loose clasp is a half-hour job for a jeweler. That is the alloy, not luck.

There are two metals in our workshop, stainless steel and brass, and everything large and warm in color goes to brass. Its yellow tone turned out to be the native background for labradorite, whose copper and blue flashes seem to carry on into the metal. Cold steel cannot do that, and here the stones decide the metal more often than the other way round. In the “KHALISI majestic” bracelet at 22,000 ₽ the brass is set with labradorite and moonstone, both feldspars, both intolerant of abrasive cleaning. Where the play of labradorite comes from we took apart in a separate article.

The “Dragon Wing” necklace is built from twelve strands of labradorite on brass findings and costs 39,000 ₽. Brass has a density of about 8.5 g/cm³, and at this size that is the limit past which a thing stops being worn. The metal itself is cheap and takes a small share of the price: you pay for the stones and the hours of assembly. We string everything ourselves, and a second necklace exactly like it would not come out even here, because the strands fall their own way every time.

The care that settles almost everything

The rules look banal right up to the day you break one.

• Brass goes on last. Cream, perfume, hairspray and sunscreen all come before it.
• Hands wet from washing get dried completely before the ring goes back on.
• A minute with dry flannel or microfiber after wear is enough, and that minute pushes the next cleaning back by months.
• We put every piece into a velvet pouch, and the pouch is also the best place to keep it at home, dry and apart from everything else.
• A bathroom shelf remains the worst place in the apartment for any metal.

Stones set in brass are a separate matter, and their rules are not the rules for the metal. What you can and cannot do with rose quartz and labradorite is set out in the guide to caring for stones. The short version lives in the Care section.

How to clean brass at home

Before you take on any cleaning, there are two substances brass cannot tolerate. Abrasives are ruled out completely: tooth powder and the rough side of a sponge leave a web of fine scratches, and only a jeweler’s re-polish will remove it. Ammonia is more dangerous still, because it causes stress corrosion cracking in brass. Brass cartridge cases began splitting in India in the late nineteenth century, stored near stables and cracking through in the damp season from ammonia fumes. The cause was found in the nineteen-twenties and named season cracking, and ammonia glass cleaner has been kept away from brass ever since.

The third prohibition concerns stones and costs more to break than all the others. Where a stone sits next to the brass, acid is off the table entirely. On a piece with stones the metal is worked spot by spot, with a cotton bud in soapy water. The stones get only a dry soft cloth.

For a piece without stones the home recipe is short and costs about thirty rubles.

1. Dissolve a drop of liquid soap in warm water and wash the piece with a soft toothbrush.
2. Dry it completely: water left in the relief will bring the tarnish back within a couple of days.
3. If the darkening is still there, mix a teaspoon of baking soda with the juice of half a lemon into a paste.
4. Put the paste on the metal, wait a minute, no longer, and rinse with warm water.
5. Dry it completely again and polish with dry flannel until it shines.

This is exactly the order we recommend, and ready-made copper pastes do the same thing, only for more money. If the shine has not come back everywhere, repeat the whole cycle: the second pass is always gentler than the first and leaves fewer marks.