Pearl anniversary: what the 30th year means and what suits it

Thirty years sits between two better-known milestones. The silver anniversary was five years ago, and the ruby anniversary is still ten years off. So the pearl anniversary gets overlooked, although it often falls at a distinctive point in life: the children are grown, sometimes the first grandchild has arrived, and there is room again for plans made by just the two of you.

This guide explains the name and the popular explanation of it that is wrong, suggests ways to mark the year, offers wishes to copy and sorts gifts by budget, with notes on buying and caring for pearls. It also covers the one country where a thirtieth brings an official message. The names of all the other years are in the list of wedding anniversary names by year.

A pearl forms when something foreign gets into the soft tissue of a mollusc, usually an oyster or a freshwater mussel. The animal protects itself by coating the intruder in nacre, a mix of the mineral aragonite and an organic binder, laid down in extremely thin layers one over another. The lustre comes from the sum of those layers. With cultured pearls a person starts the process; the growing is still done by the mollusc.

The image for a marriage is obvious: thirty years build up around a core, and the value lies in the number of layers rather than in any single one. Less often mentioned, and arguably more fitting, is the beginning. A pearl starts with an irritation that is not expelled but wrapped up and turned into something valuable, a description plenty of couples would sign after three decades.

What isn't quite true: the familiar story of the grain of sand. Natural history museums such as the Smithsonian point out that molluscs are good at getting rid of sand; the usual trigger is a parasite or a stray fragment of the animal's own tissue.

The name itself is settled. The traditional American and British lists both give pearl for the thirtieth year. The so-called modern list, a twentieth-century American invention, gives diamond instead, which is why US wedding magazines often print both. And the old superstition that pearls bring tears was about a bride wearing them on her wedding day, not an anniversary named after them.

There is no set format and certainly no obligation to throw a party. What works tends to suit this stage of life:

1. The children host. After thirty years the children are often adults themselves and can put on the dinner their parents used to cook. For many couples that reversal is the real present.
2. Go back to the honeymoon. Same place, thirty years on. Whether it has changed or not, it gives you a week's worth of conversation.
3. Head for the coast. Pearls come out of the water, and a few days by the sea suit the name.
4. Throw the party you missed. If the silver anniversary was lost to a house move, an illness or a crisis at work, the thirtieth is a good second chance.
5. Renew your vows. A short blessing in church or an informal ceremony with a celebrant; the options and the order of service are in the guide to renewing your wedding vows.

One idea that costs little and lasts is a string of memories. The family asks thirty people from the couple's life for a short memory or a photograph. Each card is hole-punched and threaded onto a ribbon like a pearl, and the couple read them one after another on the evening itself. Bound instead, the contributions make a small photo book, but allow three to four weeks for collecting and printing.

For the first toast: the stream of fine bubbles in champagne is called the perlage, from the French for pearl.

A card for a thirtieth can look back a little more than in earlier years. How to structure it is explained in what to write in a wedding card. The wishes below are original and free to use:

• From the children: "Mum and Dad, thirty years, and we've been around for most of them. We notice what you gave us every single day, even when we don't say it. So we're saying it today: thank you, and happy pearl anniversary."
• From the grandchildren, with a little help: "Dear Grandma and Grandpa, you have been married for longer than Mummy has been alive. You are our favourite couple in the whole world!"
• From friends, warm: "Thirty years of you two, and still that same look across the table when one of you tells a story for the third time. Here's to many more evenings in your kitchen."
• From friends, with a wink: "A pearl is what you get when an oyster is irritated by something for years and refuses to give up. We'll say no more. Happy 30th!"
• From a brother or sister: "When you two got married, we gave it a fighting chance. Thirty years later we can confirm the result. Cheers to you both."
• From neighbours or colleagues, formal: "Warmest congratulations on your pearl anniversary. We wish you both good health, time for each other and many more happy years together."
• From one partner to the other: "Thirty years, and you're still the first person I want to tell when anything happens. Layer by layer, year by year, I'd choose every one of them again."
• Short, for a text or a gift tag: "30 years, and every one of them added to the shine. Happy pearl anniversary!"

To make any of these your own, swap the general line for a shared memory: the first flat, the holiday when it rained every day, the song from the first dance. In the US, "Mom" replaces "Mum", and the rest travels unchanged. More wording for partners, parents and friends is in the collection of anniversary wishes.

Pearls are the obvious present but not the only one. Prices are rough ranges and depend heavily on type, size and quality.

Up to about $50 / £40

• A bottle of traditional-method sparkling wine with fine bubbles and two good glasses.
• A single freshwater cultured pearl as a pendant on a simple chain.
• The string of thirty memory cards, made by the family.

About $50 to $300 / £40 to £250

• Pearl stud earrings or a bracelet of freshwater cultured pearls.
• Cufflinks or a watch with a mother-of-pearl dial; pearls don't have to be for one of you only.
• A weekend on the coast with dinner by the water.

More than about $300 / £250

• A necklace of saltwater cultured pearls such as Akoya, which usually cost considerably more than freshwater pearls of a similar size.
• A trip to the sea or a return to the honeymoon destination, paid for jointly by the family.

How to tell good pearls

Cultured pearls are real pearls grown inside a mollusc; imitations are usually glass or plastic beads with a shiny coating. The rough home check is the tooth test: rubbed gently against a tooth, real pearls feel slightly gritty and imitations smooth. It isn't reliable, so expensive pieces should come with a grading report or a reputable jeweller's opinion. When comparing, the things that matter most are lustre, surface and how well the pearls match one another.

Looking after pearls

Pearls are soft and sensitive to acids. The Gemological Institute of America (GIA) advises keeping hairspray, perfume and cosmetics off them, wiping them with a very soft cloth after each wear, and never putting them in an ultrasonic or steam cleaner. Warm soapy water is fine for an occasional thorough clean, as long as a strung necklace is completely dry before it is worn again. Those instructions are worth tucking into the gift box on a small card.

Is there an official message for a 30th?

In most English-speaking countries, no. The King's messages in the UK start at the sixtieth anniversary, the White House greetings form in the US covers the 25th, the 50th and later years, and Australia's official messages begin at fifty. The exception is Canada: the Prime Minister's office sends congratulatory certificates to Canadian citizens for the 25th anniversary and every five years after it, so a pearl anniversary qualifies. The request goes in online, at least six weeks before the date. Catholic couples anywhere can also order an Apostolic Blessing on parchment for a thirtieth from the Vatican's Office of Papal Charities, which puts the proceeds into its charitable work.

Special cases

• One of you doesn't wear jewellery. Bubbles in a glass, mother-of-pearl on a watch or the sea do the job. The name is a prompt, not a shopping list.
• Someone in the family thinks pearls are unlucky. No need to argue. A mother-of-pearl gift or a trip does the same job.
• The couple want no fuss. A card, a phone call, a bunch of thirty stems. That is enough, and nobody should organise a party that nobody asked for.
• The marriage is going through a hard patch. If you know the couple are thinking of separating, leave out the lines about thirty happy years and simply write that you are thinking of them both.
• One partner died before the anniversary. The date still matters to the one who is left. A short message such as "It would have been thirty years today. I'm thinking of you, and of him" shows that someone remembered. Staying silent out of awkwardness leaves them alone with the day.

Looking further ahead: ten years after pearl comes ruby, and twenty years after it the golden anniversary. The full list of names helps get the next dates into the calendar in good time.