A word from experience
Pragmatically, it is far better to break any rule on this page than to lose a precious piece of jewelry. Rings are lost at public sinks and in gym lockers, not at the bench. Wear your jewelry. Enjoy it. And only rarely take a risk your jeweler wouldn't approve of.
Every stone has two kinds of strength, and the trade usually speaks of only one. Hardness, measured on the Mohs scale from talc at 1 to diamond at 10, is a stone's resistance to being scratched. Toughness is its resistance to breaking when struck. The two are independent of each other and are sometimes opposed: diamond is the hardest substance in nature yet cleaves along four perfect planes, while jade can be scratched by a steel blade and will survive a hammer.
The chart is best read by its corners. The upper right holds the stones that can be worn every day without a thought; the lower left holds those for which one chooses the occasion. Emerald, opal and tanzanite sit low, and alexandrite high. Diamond and sapphire sit together near the middle, and their order is debated: by measured fracture toughness, diamond is several times tougher than corundum except along its cleavage planes, and at the bench we see more chipped sapphires than diamonds, because the softer stone wears its edges first. Both deserve the same care, which is to keep hard knocks away from the girdle.
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For each stone, the rule and the exception.
Clean with warm water, a drop of dish soap and a soft toothbrush worked beneath the setting. A diamond in a sound setting may safely go in an ultrasonic cleaner.
Diamonds are almost never scratched, but a sharp knock against a hard surface can chip the girdle, the thin edge of the stone. Remove rings before the gym and the dishwasher.
Clean with soap, water and a soft brush. Heated stones may go in the ultrasonic; an unheated stone with fine fissures should not, and your laboratory report states which you have.
Sapphire is many times softer than diamond and, at the bench, chips more often. On a ring worn daily the facet edges wear first, and a worn edge is where a chip begins, so we recommend that the corners be checked every few years.
Clean with lukewarm water, mild soap and your fingertips, then pat dry. An emerald must never be placed in an ultrasonic or steam cleaner, and should be kept from hot water and hot tubs.
Most emeralds in the world are oiled. We specialise in stones with no oil or an insignificant amount, and the report states the grade. When an oiled stone begins to look dry, we send it to a specialist to be re-oiled, and it returns as it was.
Clean with a damp cloth, followed by a dry one, and nothing else.
Opal is three to ten percent water. Australian opal is not hydrophane, which is to say it does not absorb water or lose its colour when wet, and it is far more stable than Ethiopian opal, which does both. Keep it from dry heat, sudden cold and hard knocks. For a long stay in a very dry safe, a damp cotton pad in the bag keeps the air from drawing moisture out of the stone.
Pearls go on last and come off first. Wipe each pearl with a soft damp cloth after wearing and lay the strand flat.
Nacre is organic, and acid etches it: perfume, hairspray and the perspiration of a long evening are the reasons for wiping pearls after they are worn. Nacre also needs a little moisture to stay supple, and skin provides it, which is the reason for wearing them. A strand worn often keeps its lustre; one shut in a dry drawer for years loses water from the nacre and can crack.
Clean with soap, water and a soft brush, and more often than you would expect: tourmaline is pyroelectric, and when warm it draws dust to itself.
Paraíba tourmaline is usually included, and inclusions are where heat and ultrasound do harm. Treat it as you would an emerald, with lukewarm water, no heat and no ultrasonic cleaner.
These are the stones to choose for a ring that is worn every day. Clean with soap, water and a soft brush; all three may go in an ultrasonic cleaner in a sound setting.
None of the three is routinely treated or oiled, and none requires special handling. Their only vulnerability is the one every stone shares: a hard blow on a thin edge.
It is the metal, rather than the stone, that wears in a piece of jewelry. Gold scratches from the first day and polishes back; platinum does not lose metal when scratched but moves it, and develops a soft patina that can be polished away or kept.
Chlorine, in bleach and in swimming pools, weakens a gold shank over the years. Titanium is light, hypoallergenic and far more resistant to scratching than gold, but it cannot be soldered or resized at the bench, so the size must be right from the start.
An ultrasonic cleaner produces some forty thousand collapsing bubbles a second, and those bubbles cannot tell soap scum from a fissure. For the right stone it is the best thirty dollars you will spend on your jewelry; for the wrong stone it is the most expensive. The whole answer follows.
Three to five minutes in warm water with a drop of dish soap. Afterwards, check the prongs under a loupe: the machine will find a loose stone before you do.
Fine fissures, cleavage planes and old foil-backed settings are where the bubbles do their work. Send us a photograph and a sentence about the stone, and the answer is usually quick.
Oil, water, organic material and sealed air each either leave, enter or expand in the bath. These are the stones to clean by hand, as we do at the bench.
Before wearing it again
A simple test: hold a piece close to your ear and shake it gently. A loose stone makes a faint click, like a very small maraca. If you hear it, or if you are ever in doubt, do not wear the piece. Text us a photograph first, and we will set it right.
None of these is expensive or hard to find, and all of them are on our own bench. We do not sell them and earn nothing if you buy them; the links lead to the places most people already shop.
The machine we recommend to clients. The tank holds a bracelet, it comes with a lid and a basket, and it switches itself off. For a ring or a pair of earrings it does what a machine ten times the price does.
Find it on Amazon →Larger and quieter, with a proper basket and a heater that should be left off. The better choice for a collection of several pieces cleaned every week.
Find it on Amazon →Pump the foam onto the piece, brush, and rinse. It is safe for the stones the machine is not, including pearls and opal, provided it is kept to the metal and rinsed promptly.
Find it on Amazon →A cleaning gel fed through a soft brush reaches beneath the stone, where hand cream collects. For diamonds, sapphires and other hard stones only; a minute's work before an evening out.
Find it on Amazon →Impregnated with a fine abrasive, it brings up gold and platinum in a minute and lasts for years. Use it on metal only, never on a stone, and never on rhodium-plated white gold, which it will wear through.
Find it on Amazon →Softer than the Sunshine cloth and safe on plated pieces. Keep it in the drawer with the pearls, for their clasp.
Find it on Amazon →A baby toothbrush reaches beneath a setting without scratching; the original blue Dawn is the dish soap on every bench in the trade; and a ten-power loupe is how a lifted prong is found a week before it lets go of a stone.
Find a loupe on Amazon →If you are unsure about a stone, a setting, or a cleaner, ask before you try it. A photograph and a short message are usually enough for us to tell you what is safe.