Views from, and of, Florence
The Florence skyline is dominated by the dome and bell-tower of the Duomo, or Santa Maria del Fiore, the large cathedral in the centre of the city. Geochemists here this week for Goldschmidt2013 will be negotiating the sometimes chaotic streets of the town, often navigating by the Duomo’s high profile as a landmark.
But as you reach the “rock face” of the cathedral most obvious is the dramatic patterning played out by its stone facade. Three rock types have been used to face the Duomo. A green metamorphic serpentine, white Carrara marble, and a red limestone.
The Tuscan serpentine is, perhaps, the most striking. Its deep green hues draw the eye. It is mottled, with a dull darker green groundmass and lighter areas and white veins run through it in places. As a building stone, it is given the name Verde di Prato. Quarried from Figline, a village near Prato, about 18 km north-west of Florence, it was added as a decorative exterior to the Duomo in the 14th century.
It is a coarse serpentinised peridotite. Some blocks show evidence of the former olivine and pyroxene crystals, and the veining is reportedly quartz.
t has been used extensively as a decorative facing stone elsewhere, and not just in Italy. For example, in the UK can be seen lining of the back of the reredos of St Paul’s Cathedral, London, and in the new portion of the National Gallery, Trafalgar Square. The altar of All Souls’ Roman Catholic Church, Peterborough is made of the same serpentine, and samples are kept in a number of museum collections. Henry Moore sculpted “Head and Shoulders” from a block of it in 1927.
The red limestone provides additional detail to the Basilica facade, acting as a highlight. And if you turn your head sideways you might even mistake it for a flagstone…
About the author
Simon Redfern, University of Cambridge, UK
I’m a Mineral Physicist, which means I enjoy applying an understanding of the properties of Earth materials at the atomic scale to a wide range of problems across Earth’s history, on global scale. By studying interactions across varying length scales and time scales I aim to understand how our planet works. I will be talking at Goldschmidt on Monday afternoon, about how synchrotron X-rays can be used to image the geochemistry of plankton calcite shells at the nanoscale. This year I have enjoyed a stint as a British Science Association media fellow, which has involved working at the BBC Science & Environment desk learning about science communication, and I also blog on the EGU network. All this activity started as blog at Geopoem for my students, and I post things there still. I’ll be tweeting, when I have a moment, as @Sim0nRedfern.
We’re aiming to provide a wide coverage of Goldschmidt 2013 via our blogging and tweeting, but make sure you also keep an eye out for the official press releases coming throughout the week.