The travertine quarries that built ancient Rome are carving rock for a new generation of temples

TIVOLI, Italy — Long ago, when Romans wanted to build a new temple, they would head to the nearby quarries of Tivoli, chisel out blocks of porous rock called lapis tiburtinus — now known as travertine — and float the cargo downstream on rafts to craftsmen in town.

That's how they made the Colosseum 2,000 years ago. That's how they made St. Peter's Basilica and Bernini's great colonnade hundreds of years later.

Today, the same quarries that built Rome with their distinctive pock-marked travertine are still being dug out to build a new generation of churches, temples and mosques around the world — as well as banks, museums, government buildings and private homes.

While other countries have versions of the sedimentary limestone, Roman travertine is unique because it is quarried underground in the sulfuric springs and basins around Tivoli. Made up mostly of calcium carbonate minerals, Roman travertine was formed hundreds of thousands of years ago by deposits of calcium, sulfur and other minerals, and shows the region's history of volcanic eruptions, forests and fossils in its striated layers.

It is prized by architects for a number of reasons: It's strong, plentiful and can withstand any number of climactic and environmental assaults. Depending on how and where it's cut, it has a variety of looks: rough or sleek, from a warm white with irregular black holes to sandy beige with gray, brown or even greenish veins.

A new Latter-day Saint temple in travertine

For four generations, the Mariotti Carlo SpA stonecutting firm has been carving travertine to order, fulfilling some of the world's most distinctive architectural commissions: the Getty Center in Los Angeles, the Bank of China headquarters in Beijing, the Great Mosque in Algiers, Algeria, to name a few.

After providing the travertine for the Latter-day Saint temple in Rome, Mariotti was chosen by the church's architects to restore the temple on Manhattan's Upper West Side. The temple sits across Broadway from Lincoln Center and the Julliard School, both built with Mariotti-cut travertine decades ago when the rock first reached the U.S. market.

''Travertine is a classic stone known all over the world. It's a bit like carrying the light of Rome everywhere, because the way travertine reflects light is very special,'' said Fabrizio Mariotti, head of the family business.

A quarry that Bernini loved

All around the Tivoli quarries, the air is heavy with the stench of sulfur and the constant pounding, clinking and cracking of giant jackhammers blasting ancient rock into pieces.

At the Degemar quarries, drilled down to 30 meters (yards) under sea level, bright blue ponds of sulfur springs pool the travertine residue as flat-bed trucks haul stone slabs weighing 33 tons up to street level.

Bernini spent so much time here selecting his rock that he had a home overlooking the quarry, which still stands today.

The quarry's current head, Vincenzo De Gennaro, reminds visitors that Bernini's tower still features the coop for the homing pigeons that would transport the orders to the quarry from Rome for the measurements of rocks that were needed.

Nowadays, the quarry is filling orders much farther afield: the new airport in Riyadh, Saudi Arabia, the new headquarters of China's governing party in Shenzhen, among others.

''It is special, a special stone because it is a living stone, a stone that is born in a cocktail of mineral waters,'' De Gennaro said as he dodged earth movers and walked among the sulfur pools.

A 2,000-year guarantee

''There is the concrete experience of a civilization dating back thousands of years that stands in the light of day and has been shining undisturbed for 2,000 years,'' he said. ''That is the guarantee.''

Marco Ferrero, professor of civil engineering at Rome's La Sapienza University, said part of travertine's appeal is that it harks back to ancient Rome ''and therefore also to the magic of the classical world.''

He said it embodies Rome's spirit in many ways: Travertine is solid, resistant and noble but not showy like its cousin, marble, which doesn't fare as well over time when exposed to the elements.

''We can make this comparison: Marble speaks to us in beautiful Italian, in literary Italian, while travertine speaks to us in Roman dialect,'' he said. ''It is truly the stone of the Romans. And like Roman cuisine, which is made up of simple dishes, often using discarded ingredients, travertine is a genuine and traditional stone.''

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