Prominent among these were the Medici who, during the 16th century, built up a unique collection of objects — from bowls, goblets and jugs to inlaid pictures and furniture — made from and adorned with this precious stone.

Image A cup with gold mountings, from Florence, circa 1600. Credit... Ashmolean Museum, Oxford

The collection now forms the centerpiece of an absorbing and sometimes dazzling exhibition, “Lapis Lazuli: The Magic of Blue,” that stretches from the third millennium B.C., in the form of a royal seal from Mesopotamia, through the Middle Ages, the Renaissance and Baroque periods to the search for synthetic blues in the 19th century and the revived use of genuine lapis lazuli by jewelers in the 20th and 21st centuries. The show was curated by Maria Sframeli, Valentina Conticelli, Riccardo Gennaioli and Gian Carlo Parodi, and continues until Oct. 11.

The first section of the show, “From Nature to Artifice,” opens with raw samples of rock, illustrating the wide variety of patterns and colors it manifests. There follow nearly 20 examples of lapis jewels, amulets and statuettes from ancient Mesopotamia and Egypt, all of them small in size and reflecting the extremely limited availability of larger pieces of rock at that time.

Ground lapis lazuli was increasingly used by painters during the 13th and 14th centuries to make ultramarine and Cennino Cennini gives instructions on how to prepare this pigment in his “Book of Arts.” But it was not until the second half of the 16th century that large objects carved from lapis began to appear in Italy. The first center of production was Milan where the Miseroni brothers, Gasparo and Girolamo, became famous for their mastery of working this challenging material. Half a dozen of the pieces acquired by Grand Duke Cosimo I Medici are on show here, including the “Cup in the Form of a Shell” referred to in a letter of 1563.

Cosimo’s successor, Francesco I, brought craftsmen from Milan to carve lapis in Florence in the early 1570s. Francesco expanded the Medici workshop for the production of these objects, which continued under his brother Ferdinand, who succeeded him in 1587. There is a stunning array here of these ornamental pieces, exquisitely carved and substantial in size. In 1588 Ferdinand reorganized the Medici workshops and enlarged the scope of their productions. He had spent many years in Rome, where he developed a taste for intricate inlaid table tops. He now employed the skills of his designers and craftsmen to create some extraordinary landscape table tops, which fully exploited the natural patterns of lapis to represent foam-flecked seas and skies with billowing clouds, such as the “View of the Port of Livorno” and “Tuscan Landscape,” both on show here.