Q. I just saw an ad on the Internet for “mourning jewelry,” which stopped me in my tracks. What is it? I’ve never heard of it before.

Although the idea may seem strange to us today, mourning jewelry has been around for centuries. Before photography, mourning rings and other pieces (often containing a lock of the deceased’s hair) were the only tangible ways to hang on to a loved one’s memory. Unlike other jewelry, the items were inscribed with the deceased’s name and date of death. Sometimes hundreds of rings were passed out to attendees at the funerals of the wealthy in England and elsewhere in Europe.

Mourning jewelry first became a burgeoning industry around 1649, when England’s King Charles I was executed, according to Sarah Nehama, author of “In Death Lamented: The Tradition of Anglo-American Mourning Jewelry.”

“Charles was considered a martyr by many. The inside of his mourning ring was inscribed, ‘Prepared be to follow me,’ a reminder that life on earth is finite,” she says.

Mourning jewelry peaked in popularity in the Victorian era when mourning was very public. After her husband, Albert, died, Queen Victoria launched a strict code for mourning clothes and conduct. Jet mourning jewelry was the only jewelry permitted to be worn by members of the court in the year following Albert’s death. The queen herself grieved for the remainder of her life.

Nehama notes that attitudes toward death have changed dramatically in our society. People used to be exposed to death in their homes, especially the deaths of children. As dying moved out of the house and into hospitals and hospices, we were shielded from the reality of the death process. Death became something fearful, and photo albums preserved memories of loved ones.

You can buy antique mourning jewelry, including rings, pendants, necklaces, earrings, and other items, for as little as $50 — on up to the tens of thousands of dollars — depending on rarity, age, historical significance, and materials. The custom of mourning jewelry was imported to the American colonies, and Nehama recently saw a gold-plate and enamel brooch with a portrait of George Washington priced at about $1,000. She bought on eBay a ring that was made in 1737 for Queen Caroline, the wife of George II. And yes, it contains the queen’s hair.

“Men wore watch chains made of human hair, which is indestructible,” she adds.

New mourning jewelry is also available today, such as pendants and lockets that contain the deceased’s ashes. Or ashes can be turned into diamonds. People have even asked Nehama, who is a jeweler, to make mourning jewelry in memory of their dogs.

Florence Isaacs is the author of several books on etiquette, including My Deepest Sympathies: Meaningful Sentiments for Condolence Notes and Eulogies. She writes two advice blogs for Legacy.com: Sincere Condolences and Widow in the World, a blog for bereaved spouses and partners. Have a question for Florence? Send her an email.