When speaking of the architecture of the Roman Empire, many people think of white marble statues, columns and terraces. Interestingly, although marble was used in many buildings and squares at the time, it was not used in the pure white version, but in the more colorful version. Ciboea, for example, has a green vein, called Cipollino Verde, extracted from the Greek island of Euboea. Since marble is very expensive, it is usually shipped on top of other, less expensive stones, with proper board protection.
Professor Ces Passchier, from the JGU Institute of Geological Sciences, said: "So far we have not found the remains of a marble workshop from the Roman Empire. But by analysing wall finishes dating back to the second century AD, this study can still shed light on the way marble was mined and processed."
An international team of researchers from Mainz, Turkey and Canada have completed an analysis of the marble facade of the second century Roman villa, detailed in the online edition of the journal Archaeological Science Reports.
To do this, they also relied on special software typically used to model geological structures in 3D. It was found that the material loss caused by the production of marble slabs at that time was probably much lower than it is today.
During the visit, researchers examined, photographed and measured 54 restored Cipollino Verde marble slates, each measuring 1.3 square metres, that had adorned the walls of a villa in Ephesus on Turkey's west coast.
Saw marks on one of the marble panels suggest the slabs were cut in a hydraulic sawmill (similar in principle to today's hydraulic metal saws).
The team was able to come to another conclusion after remodelling the panels with reference to them. That is, from a piece of marble stone weighing 3 to 4 tons, the ancients could cut out a total of 40 marble slabs.
They are then placed on the walls in production order and arranged side by side in pairs of books to create a symmetrical pattern.
Finally, with the help of software, the researchers were able to create a three-dimensional model of the marble block, which allowed them to reverse-engineer information about the production process and the material waste during it.
The ancient Roman Empire produced less scrap marble than it does today
The thickness of the slab is about 16mm, and the gap caused by sawing and subsequent polishing is about 8mm wide, implying that the material lost during the production process accounts for about a third, but that is still far less than many modern marble production methods today.
And although 42 panels can be sawed out of one raw material, the breakdown of the finished product mounted on the wall means that the loss from subsequent polishing or shipping is around 5% (still far less than today).
In summary, Passchier hypothesizes that the entire marble was transported to Ephesus, where it was cut and polished.