Nothing is wrong with your stone
Rings look dull after a year or two of daily wear and people assume something has degraded. Nothing has. Diamond is the hardest material there is and it does not tire.
What has happened is a film. Hand cream, soap residue, sunscreen, the oils your skin produces continuously. It builds up underneath the stone as much as on top, and because a stone works by taking light in through the top and returning it off the back facets, a coating on the underside kills the effect far more efficiently than a coating on the front.
Which is why a ring can look clean and still look dead. You have been cleaning the side you can see.
The method, which is boring
Warm water, a drop of ordinary washing-up liquid, and a soft toothbrush kept for this purpose. Soak for a few minutes, brush gently, paying attention to the underside of the setting and the space between the stone and the metal, rinse in warm water, dry with a lint-free cloth rather than a towel.
That is the whole of it. Knowing how to clean a diamond ring at home is not complicated, and done every few weeks it does most of what a professional clean does.
Do it over a bowl rather than a sink. Rings go down drains at a rate that would astonish you, and it almost always happens during cleaning.
What quietly does damage
Toothpaste. It is abrasive. It will not scratch a diamond and it will dull a polished metal surface over time, particularly gold.
Bleach and chlorine. The genuinely serious one. Chlorine attacks the alloys in gold over repeated exposure, weakening the metal at exactly the places you cannot see — claws, joints, the base of a setting. This is not a same-day problem. It is a years-later problem in which a claw fails for no apparent reason. Take rings off for swimming pools, hot tubs and cleaning products.
Ultrasonic cleaners at home. Effective, and effective at loosening things. On a setting already slightly worn, an ultrasonic bath can complete the job. In a workshop the ring is examined first. At home it is not.
The gym. Gripping a bar with a ring on it deforms the band and hammers the setting. Most visibly damaged rings we see were damaged this way rather than by anything dramatic.
Sleeping in it. Less serious, but rings snag on bedding and thin over years of friction against a mattress.
The check that actually matters
Cleaning is cosmetic. This part is not.
Once or twice a year, hold the ring next to your ear and tap it gently. A stone that has loosened in its setting will rattle, faintly. It is the crudest test in jewellery and it catches the failure that costs the most.
Then look at the claws in good light. What you are looking for is a claw that has worn thin at the tip, or sits at a different angle from its neighbours. Claws are consumable — they wear down, and they are meant to be re-tipped periodically. A ring worn daily for a decade will need this at some point, and it is a small job at the right moment and a much larger one afterwards.
If anything moves, stop wearing it until it is looked at. A stone that rattles today comes out eventually, and it does so without warning.
Why this matters more for the pieces we make
Most fine jewellery is worn occasionally. The pieces here are worn every day, which is the point of them and also the thing that wears them.
And a commission grown from someone's own carbon is not replaceable. We could make another ring. We could not make that stone again, because the appointment it came from has already happened and cannot be repeated. Insurance covers the value and does not cover the object.
So the care is not fussiness. It is the difference between an item that can be replaced and one that cannot.
A note on settings, before you buy
Half of ring maintenance is decided at the design stage.
A stone set low, or flush into the face of a signet, is protected by the metal around it and survives daily wear far better than a raised setting. The entry on signets makes this case for men's pieces, and it applies just as well to anything worn on a working hand.
Bezel settings — where a rim of metal surrounds the stone rather than claws holding it — are the most robust arrangement there is. They show slightly less of the stone. On a ring that will be worn through the next forty years without coming off, that is a trade many people would take if anyone offered it to them.
If you are still deciding, the collection shows how these choices resolve, and it is worth saying out loud at consultation that you never take rings off. It changes what should be made. Tell us that early rather than after.