Formation by Nature
The Romans began quarrying Carrara marble over 2,100 years ago. Initially, stone masons wedged moistened wood blocks into the stone's natural crevices. The wet wood would expand in the crack and release the marble. The process evolved into drilling holes with pickaxes and hammering out the slabs, and then to using handsaws.
Amid the cavities of the quarries are more than 70 varieties of minerals---wurtzite, quartz, dolomite, calcite, gypsum and fluorite, to name a few.
When first quarried, Carrara marble has a fresh, sparkling quality that inspired the name "la pietra viva," or living stone. At that point, it's also in a much more malleable state for sculptors to form.
Quarrying
This huge block of crystallized calcium carbonate, recognized as Carrara marble, originated during the Jurassic Period. Over the method of a billion elderliness, the shells of marine organisms had amassed to devise limestone. As the existence's tectonic plates merged, the heat, friction and power caused the sedimentary limestone to re-crystallize, and metamorphic marble mountains surged from the sea.The most coveted Carrara marble is the purest ghastly, called statuario, which is 98 percent calcite. Non-calcite minerals such as sand, iron oxide, manganese and clay build colourful veins and streaks in other Carrara marble. These types count bianco (clear), arabesco (with gray), calacatta (with tan), cipollino (resembling the onion, with gray and green veins), bardiglio (darker gray) and bianco venato (white with gray). In the 16th century, explosives were used, and this practice continued until the 1930s. A hydroelectric plant built in 1910 industrialized the area, and in the 1950s, the introduction of diamond-toothed wire saws further refined the process.
Formation by Art
Michelangelo visited Carrara to pick out his own marble. Following the precept that the artwork actually existed within the stone and his job was to reveal it, he sculpted his masterpiece David from a huge slab of Carrara marble with a mallet and a toothed chisel. (Chisels can also be pointed, round or flat.)
To refine the work, sculptors use files, pumice or sandpaper.
Other masterpieces of Carrara marble include Trajan's Column and parts of the Pantheon facade in Rome, the Marble Arch in London's Hyde Park and the Robert Burns statue in Dumfries, Scotland.
