Impressive Stone Floors Start As a Mountain

October 28, 2009

It’s a long journey for the stone that Apple’s architects selected to enhance the retail stores, mined from a mountain quarry in Italy, precision cut into individual pieces by craftsman in nearby workshops, and then shipped in crates to new Apple stores around the world. Now it’s revealed that the process of creating the stone floor tiles and large wall slabs falls to the Il Casone quarry, formed in 1962 by four stonemason families with generations of experience in creating subtle beauty from rough rock. The company’s quarry is north of Florence in the small town of Firenzuola, in the heart of a geologic region of sandstone called Pietra Serena. The blue-gray color of the stone, its texture and tone all contribute to the overall look of the finished Apple store.

Stone has been hewn out of the mountains around Firenzuola for centuries, and the sandstone has been used for projects both ancient and new. Il Casone has contributed to the ultra-modern offices of Cartier in Paris, the Museum of Modern Art (NYC) and the Piazza Verdi in Trieste (Italy).

Histocially, Pietra Serena sandstone was used extensively during the Florentine Renaissance, and used for both interior and exterior features. Several palazzos, or private mansions, were built from this sandstone, including the Palazzo Vecchio in Florence. Other historic buildings and churches in Italy used the stone for flooring, stairs and columns.

The challenge for stonemasons is to take the heavy, rough and large stones, and to convert them into pieces—usually smaller—that provide the needed architectural features. Sometimes that means making the massive stone look lightweight or even fragile.

Il Casone says their results are obtained, “through the combination of the traditional manual experience with the most advanced technology available in this field. ” Their Web site explains that, “The balance between the two allows for an ample range of workmanship and materials, from urban decoration to modern architecture, from restoration to substitution and restoration with ancient manual techniques.”

The Northern Apennines were created by uplift from the sea between five and 10 million years ago. Outcroppings of the sedimentary rock have been created by rivers and streams over time, making perfect locations for the 50 or so quarries around Firenzuloa. Workers start with drilling and saws to cut huge blocks of sandstone from the mountains. Trucks then haul them down to the Il Casone workshops in town, and begin cutting them into smaller pieces for all types of architectural features.

Technically, the appearance of Pietra Serena sandstone is described as, “a uniform, compact material without any special structural motifs or veining.” The stone is, “appealing for its unremarkable gray, slightly bluish color, enlivened by a subtle gleam coming from the pale-colored crystals it contains,” Il Casone says.

A critical element of the quarrying and cutting process for Apple is to perfectly match the color and texture of the stone. Since the stone is a medium-toned color, any variation in lightness or darkness would be very conspicuous—tiles of different tones would make the inside of an Apple store would look like a chessboard. An exterior stone wall would looking similarly odd, with varying tones of stone.

It’s been reported that Apple purchased an entire quarry in order to reserve and guarantee that it would have a supply of stone from the same vein of sandstone, helping to insure a uniform grain and tone. More likley, Apple has reserved a portion of the Il Casone quarry for its own future needs.

In any event, every step of the quarrying process is focused on providing up to 500 matched tiles for the average mall store. Workers select the proper area in the mountain, and then select the layer to extract. Next, huge blocks of sandstone are cut from the mountainside and trucked down to the factories for further work.

The cutting process involves making smaller and smaller section of the huge slab, all carefully designed to maximize the number of final pieces, but also to insure a uniform final product.

The final cuts produce tiles that are precisely 760mm x 760mm x 20 mm, or about 29-1/2 inches square and three-quarters of an inch thick. Each tile weighs about 55 pounds, and must then be laid out in a warehouse and color matched before being accepted. Breakage can run as high as 20 percent, according to one source, making it necessary to have back-up tiles ready for shipment.

The weight of a typical store shipment composed of 20 or more wooden crates is over 22,000 pounds. Each shipment leaves the port of Livorno (Italy) and takes about 11 days to reach New York City, and much longer for some other cities of the world.

As for the final product, Il Casone is poetic on their Web site about the stone floors, including at the Fifth Avenue (NYC) store. “The glass staircase, just as modern-day computer communication, abandons gravity and rises up from the stone floor to the vault of an immaterial consistency,” the company says. “Metaphorically speaking, it is as though the stone were held down to the floor purely by its own weight, giving the rest of the architecture a new and light dimension.”

“The orderly horizontal planes of grey stone accentuate the sought-after ascensional-white emotion,” Il Casone writes of the Apple store floor. “The polished finish permits the sandstone to be solid velvet beneath the feet of the natural wood tables and of the large number of people entering and exiting the building.”

Il Casone says that Apple’s architects, Bohlin Cywinski Jackson, “prefer a regular pattern of laying (the stone tiles), without staggering any of the slabs and with very subtle joints in terms of colour and thickness. The consequent idea is to create a continuous plane. The perceptive result is a pale and orderly backdrop, whose strength and character lie in the elegance of each millimetre of surface, without ever interfering with the interpretation of places, with the avant-garde technology enclosed in chromium-plated metals and glass, or with the relationship between customer and product.”

In the end, Il Casone says that, “The combination of skilled workers and product control makes it possible to achieve any work requested by the designer,” including one of the most demanding and innovative retailers—Apple.

Watch an interactive Il Casone presentation about the production of stone at their quarry.

The Il Casone quarry outside of Firenzuola (Italy).

Large blocks of sandstone are trucked down to the workshops for cutting.

A typical Pietra Serena stone slab before the final cutting.

Final stone tiles in a warehouse where they are being laid out for color matching.

The Burlingame (N. Calif.) store with an all-stone exterior.

The Burlingame side wall, looking a little “warmer” than the actual color in the evening light.

The stone floor at the Stanford (N. Calif.) mini-store.

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