Jesus’ grandmother wore about a size 6 sandal, if the evidence on view at Baltimore’s George Peabody Library can be believed.

Among the highlights of a new exhibit of 50 of the rarest and choicest treasures owned by one of the world’s great libraries is a small, cream-colored silk pillow embroidered with silver thread, approximately nine inches long and half as wide, or a bit larger than an American woman’s size 6 shoe.

“I never thought that a silk pillow would belong in a library,” says Earle Havens, who curated “Bibliomania: 150 Years of Collecting Rare Books for the George Peabody Library,” which runs through January. “But it is a perfect embodiment of what a library can be in people’s imaginations.”

The pillow is attached by a silk ribbon to a manuscript of sorts — a piece of printed paper sealed with red wax by an anonymous church authority. The document attests that the pillow once held “the right foot in flesh and bone of St. Anne, mother of the most glorious Virgin Mary.”

A broadsheet from 1751 displayed next to the pillow declares that the cushion and foot were kept in a cathedral in Ancona, Italy, along with such other holy relics as a sliver of the crown of thorns that Jesus wore when he was crucified, the heads of saints Peter and Paul, and the miraculously preserved body of the fourth-century Christian martyr St. Cyriaco.

It’s just one of many surprises that visitors will encounter in this charming and quirky show of manuscripts spanning the 14th through the 19th centuries. Most of these books, Havens said, have never before been on public view.

The show pays tribute not only to the wonders that can be found between bound pages but to the bibliomaniacs who go to such extreme lengths in pursuit of their passion that some chained their most precious volumes to thick wooden boards.

“The whole history of books,” says Havens, curator of rare books for the Johns Hopkins University’s Sheridan Libraries, “is a history of theft, of books being destroyed by fire or flood, of mice nibbling the pages, of war and book burnings. Human beings are very good at destroying culture.

“But sometimes, something as rare as a medieval book survives to the present day despite the odds.”

Among other things, the exhibit contains an exquisitely illustrated prayer book from 1492 that was stolen from the Peabody in the first half of the 20th century, only to be returned anonymously decades later through the U.S. Postal Service.

There’s also a 14th-century medieval manuscript of Aristotle’s scientific writings that was nearly destroyed when the old Baltimore Athenaeum went up in flames in 1835.

Havens originally put together the show to entice members of a French-based organization of the world’s top book collectors to visit Baltimore during a tour of U.S. libraries.

“Our visit to the Peabody was one of the high points of the week,” said Eugene S. Flamm, a New York collector who received a preview of “Bibliomania” recently along with other members of the Association Internationale de Bibliophilie.

The show makes the point, Flamm said, that modern collectors are the 21st-century equivalent of medieval monks. Both are dedicated to safeguarding and preserving the store of knowledge that civilization has accumulated over the millennia.

“Collecting isn’t just a hobby for a bunch of rich, useless people, and not everyone who collects books is nuts,” said Flamm, chair of neurosurgery at New York’s Albert Einstein College of Medicine.

“Even with electronic media, books are an integral part of civilization. The use of a library is of great importance to people in all walks of life.”

As Havens notes, each object on view tells a story. Sometimes the story is about Baltimore, and sometimes, it’s about the wider world.

Former Walters Art Museum director Gary Vikan has spent much of his career observing the passionate investment that people can make in lifeless objects.

For Vikan, there’s a natural progression between religious relics, such as the pillow thought to have once held St. Anne’s foot, and secular relics, such as the drive to preserve an ancient scientific treatise despite the risk to life and limb.

“People think that physical things are powerful,” said Vikan, who was reached in France, where he’s putting the finishing touches on a book about the Shroud of Turin.

“Being close to the thing you love is an act of piety. The world today isn’t so different from the way it was 2,000 years ago. We still imbue objects with potency as a way to make sense out of life.”