by Jane Johnston

Pietra dura has been aptly described as ‘painting in stone’. In this astonishing work that is sometimes called pietre dure in the plural (meaning ‘hard stones’), thin slices of various stones are selected, cut to shape and set together, jigsaw puzzle-like, into a multi-coloured design.

A major site of production for this work was the Medici-established opificio (workshop) in Florence, which produced myriad and marvellous objects of pietra dura over three centuries. It became famed for it, and not only for the technical virtuosity of its precise stonework but also for its magnificent designs, typically pictorial.

Painting in stone in Florence

The opificio made Florence more renowned for pietra dura than any other city, with the result that historic works of pietra dura by the opificio are now found around the world, often in royal or aristocratic collections. You can also find its works in Florence and that includes at the workshop itself, the Opificio delle Pietre Dure, now a museum and a centre for object restoration and preventative conservation.

The story of pietra dura in Florence begins in the sixteenth century, with excitement across Renaissance Italy about archaeological excavations; wondrous things from ancient Rome were being unearthed, including patterned floors and walls made from various stones using the technique of opus sectile.

Marbles and other stones came into high fashion for interiors, and with marvellous stone from around the world already to hand in Rome and other cities on the Italian peninsula, and more able to be sourced relatively easily, the scene was set for new, antique-inspired stonework. By the mid sixteenth century, the first pietra dura had been created in Rome.

The Medici were great appreciators and collectors of ancient stonework from the time of Cosimo I (r. 1537-74), the first Grand Duke of Tuscany. His sons, the Grand Dukes and brothers Francesco I (r.1574-87) and Ferdinand I (r.1587-1609), wanted to see works of stone on par with the work of ancient artists being made in Florence too.

In 1588, Ferdinand I established the Opificio to make pietre dure and other forms of art. It was set up in the east wing of the Uffizi and originally called the Galleria dei Lavori. There, artisans worked exclusively for the Medici in a salaried arrangement that was one of the first of its type for any court in Europe. This arrangement has been credited as conducive to building and sustaining the extraordinary level of artistic skill that made the Opificio so renowned.

The Medici and the development of pietra dura mosaic

The jigsaw-like assemblages of stone that the artisans created came to be called commessi fiorentini, commesso meaning ‘fitted together’. They were created for various purposes, some simply to be pictures, others to be parts of furniture – tabletops for example, or panels in elaborate cabinets with cupboards and drawers. Still others were made for smaller objects, including caskets, trays, jewel boxes, vases and jardinières, or to be embedded into architectural elements, such as walls and mantelpieces.

The designs were initially abstract but, by the end of the sixteenth century, veritable pictures emerged, with subjects including vases of flowers, trees, birds, cornucopias, coats of arms, still life compositions, and portraits. In some designs, the spaces around the pictorial elements were decoratively embellished with non-pictorial elements. From the sixteenth century and, even more so, from the seventeenth, the Opificio created compositions that were entire scenes: urban, rural and maritime tableaux, and depictions of religious stories.

Ferdinand influenced the designs; he wanted the Florentine work to be different to what was being made in Rome, where the focus was on geometric and abstract designs. An example of this kind of Roman production is a table commissioned by Cardinal Alessandro Farnese, made ca 1565–73 from stones salvaged from ancient Roman sites, and now at The Metropolitan Museum of Art in New York. Instead, Ferdinand encouraged works of naturalism.

*The Farnese Table from The Metropolitan Museum of Art, New York City (Public Domain)*

Colours and patterns of nature in stone

Stone provided a rich colour palette with which to depict nature. Jasper, marble, alabaster, chalcedony, agate, amethyst, porphyry, fossilised wood, lapis lazuli and malachite were among the wide range of stones used, sourced by the Medici from around the world. Some were rock and others mineral, and they varied considerably in their hardness as well as value – aside from semi-precious stones, sometimes even precious gemstones like emerald and ruby were integrated into the designs, or non-stone materials such as mother of pearl or metal, especially gold.

But it was more than colour that interested the artisans. Patterning in the stones was also valued, such as to depict colour variation across a leaf, or the pattern on a butterfly wing. Or, by judicious choices of exactly which part of a stone to place where in a design, an artisan could use the light-dark variations (chiaroscuri) within a stone like chalcedony to create an illusion of three dimensions.

Translucency was another appreciated quality, for then the very appearance of the stone could be transformed. Translucent stone could be backed by coloured resin or a thin layer of metal. It could also be painted on the back, for those brush strokes to show through in the finished piece as part of the design, for instance as lines suggesting the edges of individual clouds in a stormy sky.

Inspired decisions made by the artisans about those transformations, and about exactly which portion of which stone to use where in a design, were what elevated works of pietra dura into something particularly fine. Those choices were as integral to the creation of a masterpiece as the artisans’ execution of the difficult and laborious stonework, with such amazing precision that the joins became imperceptible. (Watch this video, with English subtitles, made by the Opificio.)

Europe and the vogue for Florentine pietre dure

The Opificio produced works for the Medici properties and created impressive diplomatic gifts to be sent all over Europe. It made exquisite gifts of pietra dura that showcased the wealth of the Medici court and its skill and refinement in the arts, exemplified by the stones that were used and the evident creative and technical prowess of the artisans.

The naturalistic subject matter also reflected the Medici court’s significant interest in nature and in the natural sciences, with designs accurately depicting, for example, exotic birds that could then be found in the Grand Ducal aviaries of the Giardino di Boboli. Jacopi Ligozzi, capomaestro (head) of the Opificio from the late sixteenth century, provided some naturalistic pietra dura designs. Today, he is better known for his extraordinary works of botanical and zoological illustration, some of Italy’s earliest and most important examples of the genre.

The Opificio fulfilled the same purposes for the Habsburg-Lorraine Grand Duchy, which succeeded the Medici in 1737. The widespread recognition of the Opificio’s mastery of pietra dura that arose from that diplomatic gifting by the Medici and Habsburg-Lorraines is visible in the history of the technique elsewhere in Europe; several of the workshops of other European courts, including in Prague, Naples, Madrid and Paris, were either founded or first began to produce pietra dura after artisans from the Florentine Opificio moved to join them.

Changes in Florence, changes in an artform

However, the Opificio experienced important changes over time. It moved to its current location in Via Alfani in the late eighteenth century, and was officially renamed the Opificio delle Pietre Dure in the mid-nineteenth century.

And as fashions changed, so did the Opificio’s designs. For instance, to suit baroque tastes in the seventeenth and eighteenth centuries, the Opificio produced some works where the stone pieces had a degree of three dimensionality, and others that were sculptures fully in the round, made of multiple types of stone.

The volume and nature of the Opificio’s output also varied with shifts in the political context and power of the Grand Duchy. For example, small works of pietra dura became more common during the Napoleonic interruption to the rule of Ferdinand III (r. 1790–1801 and 1814–1824), during which the Opificio took commissions from private individuals for small objects like tiles and snuff boxes.

It was a taste of things to come, after the last of the Habsburg-Lorraine Grand Dukes to live in Florence, Leopoldo II (r. 1824–1859), departed Florence in 1859 before the 1861 proclamation of the Kingdom of Italy. In unified Italy, the Opificio continued its operations, but had to be financially self-sufficient.

Records show the challenging times that followed, as the then director strove to discover the tastes and budget of a new and mixed private clientele. Under the next director from 1876, restoration work was increasingly taken on as the Opificio’s production of new works waned and eventually stopped in the late nineteenth century.

*An early eighteenth-century landscape, designed by Baccio Cappelli (Wikimedia Commons / Public Domain)*

The Opificio delle Pietre Dure today

Today, the Opicifio delle Pietre Dure is a special body within the national Ministry of Culture. It undertakes restoration of various types of cultural objects, from Florence and elsewhere, and is now one of Europe’s leading centres for research and teaching in object restoration and preventative conservation.

The Opificio’s museum was opened in the 1880s and reconfigured in a 1990s renovation. Its collection includes a wide selection of historic works in varying stages of completion, a wondrous array of many different stones, and desks and tools once used in the workshop, as well as notes, drawings and models related to what was made.

As the Opicifio’s production spanned more than 300 years, its museum provides a fascinating reflection of several changes in style in the decorative arts, through to work showing a taste of the Art Nouveau to come.

When you have an opportunity to admire historic pietra dura works, it’s interesting to think that they still look as they did when new, thanks to the durability of their material. Contrast that with paintings, which are prone to marked changes in appearance over time, a vulnerability that’s referred to by another old and apt term for pietra dura, ‘eternal painting’.

And yet, with contemporary ‘eyes’, we can’t perceive works of pietra dura as they were when first made. Works by scholars such as Fabio Barry can help us to appreciate some of their contemporary context, such as the symbolic meanings and powers attributed to different stones.

It's also worth knowing that less costly works called scagliola were made to imitate pietre dure, first in the seventeenth century and more so after they became highly fashionable in the eighteenth. Scagliola involved inlaying stone (often black marble) with coloured plaster and masterfully beautiful examples were produced by the Opificio as well as by others in Tuscany and elsewhere.

Where to admire commessi fiorentini, in Florence and beyond

Florentine pietra dura can now be found around the world, especially in Europe and often in grand historic palaces and houses, or in museums with royal or aristocratic collections. In Vienna, a city rich in Habsburg history, there are fine examples of the Opificio’s work, including a great many in the presidential reception Pietra Dura Room of the Hofberg Palace. (Visit this page to view some of them.)

In Florence, you can still discover historic works by the Opificio in its museum and in places associated with the Grand Duchy, famously in the Galleria Palatina of the Palazzo Pitti, the Tribuna of the Gallerie degli Uffizi, and the Cappella dei Principi (Chapel of the Princes) which adjoins the Basilica di San Lorenzo and is the mausoleum of the Medici Grand Dukes. This astonishing chapel is almost entirely clad in stone and is especially noteworthy as a major project for the Opificio over more than two centuries, from around the start of the seventeenth century.

And in Florence, even in the streets around the Museo dell’Opificio in Via Alfani, you can seek wonderful examples in antique shops and in the workshops of those highly-trained Florentine artisans who still create pietra dura using traditional techniques.

Captured in stone: Florence’s mastery of pietra dura

Istanbul, Ravenna & Venice: The Byzantine Legacy