A few weeks ago, the art museum in Montpellier provided a welcome refuge from torrential rain (of course, I was planning on visiting anyway, but the weather drove me there). On the whole, I have to admit that the museum's collections were dominated by the kinds of genres and schools that I find difficult to get excited by, but there were some gems. Along one long hallway hung a series of landscapes, and, among them, I found the painting above. It's by the nineteenth century French artist Jules Laurens, not well-known outside his own country, and best-known there for his orientalist works. This one, however, I found interesting. Painted in 1869, the title is Le Sentier des sables à Fontainebleau - "The sand path at Fontainebleau." Storm clouds gather as a windblown figure is followed by his dog through what would seem to be a beach surrounded by massive craggy boulders and cliffs. It is, in a way, a beach, but one from 35 million years ago being recycled today by weathering and erosion, and it's a long way from the coast - the forest of Fontainebleau lies not far southeast of Paris.
The crags and boulders (which today provide a highly-regarded destination for rock-climbers) are made of the Fontainebleau glass sand, one of the highest quality and most renowned sources of silica sand in the world. I wrote about this in the section on glass in the book:
A visitor to Fontainebleau (where Napoleon abdicated—twice) might be drawn there by the magnificence of its château, but other treasures lie in its forest. Around thirty-five million years ago, a warm sea inundated much of northwestern Europe, and this sea retreated and returned over and over again. To the southeast, the Alps were still forming, rising from the forces of Africa crushing into old Europe. As from time immemorial, while the mountains rose, the elements chastised them for doing so, eating into the newly exposed rocks, eroding and destroying them. ..... debris from the Alps was carried northwestward by rivers to the encroaching sea, along the way grinding and sorting the sand that would be disgorged into the sea at the river’s end. This sand was then caught up in the dynamic coastal processes we saw in chapter 5, all the time being cleaned and winnowed. As the sea made its final retreat, these sands were left stranded, and they are preserved today as the Fontainebleau sandstone. The rivers and the sea had done a fine job of cleaning the sand, but water later percolating through it leached out even more of the impurities, leaving huge tracts of sand that can be over 30 meters (100 ft) thick, fine, white, clean, and all of roughly the same-sized grains—in other words, ideal for making glass. Fontainebleau has long been one of the premier glass sands in the world and today is a focus of major international glassmaking companies.
Indeed, Corning Opthalmic Glass operate a major research and production facility there, on the site where, in 1752, the Bagneaux glassworks were founded by Royal Decree. Common glass, even the colourless kind, still retains a greenish tint, particularly if looked at edge-on; this results from remaining trace quantities of iron. Fontainebleau sand starts off with a very low iron content, and so is an excellent raw material for manufacturing high-quality, specialist, glass products.
A few years ago, elsewhere in France, I visited a glass-blower's workshop and asked him what the source of his sand was. "Fontainebleau, of course" was the reply; I told him of my interest in his raw material and he very kindly provided me with a substantial bag of the sand, and a glass globule made from it. Look down the microscope and you can see the purity of it (and some rounded, frosted, grains - evidence of coastal winds 35 million years ago):
The famed Murano glass-makers of Venice long ago abandoned their own traditional supplies that cascaded out of their side of the Alps and today use Fontainebleau sand.
And, when I.M. Pei was laying down the law for the specifications of his glass pyramid design for the Louvre, those criteria (together with the traditional French insistence on things French) led inevitably to using Fontainebleau sand. The story of how the sheets of glass could only be made using long-abandoned technology (and, even then, had to be finished in the U.S.) is an interesting one and the whole project has been the subject of a brutally frank - and therefore highly entertaining - Harvard Design School case study.
So, two museums, one with a painting of the raw material, the other with a spectacular example of the product.
[Louvre pyramid image credit http://www.flickr.com/photos/sunstarrr/2118508871/; the Murano image is from http://casasadobes.wordpress.com/]