JuraLimestone GmbH, part of the construction holding STO AG, owns 9 quarries of Jura Limestone. A special quarry of this stone is located in the area of Petersbuch, near the city of Eichstätt in Germany, which was previously developed by the company Neumeyer & Brigl, a family business of Mr. Hans Neumayer and Otto Brigl, now part of JuraLimestone.
The quarry reaches a depth of about 19 m and consists of 25 layers. Here, a rare Jurassic stone of a special light beige color can be extracted – JuraLimestone® Jura Cream, which, with appropriate surface treatment, can have an almost white tone with subtle outlines of ancient fossils, giving this stone its world-famous individuality.
Gerhard Ruf - former manager of JMS, representing several Jura Limestone producers and now head of the international projects department at Jura Limestone, explains that in the quarry you can see all 25 layers and the thickness of each of them is determined by nature. “We are working simultaneously on several levels due to differences in color,” he explained. “In this quarry, there are 25 layers and very little overburden. You can count all the layers, from the first to the twenty-fifth.”
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🔍Jura Limestone, as mentioned above, has a layered structure that remains relatively unchanged over many kilometers. This primarily accounts for the relative uniformity of raw material quality for large facade projects and the homogeneity of the color palette. The main natural tones of Jura Limestone range from beige to dark beige, which are found in the upper layers from levels 20 to 25. Gray tones are also present, which are typically used for interior finishing and are located in layers from 1 to 6. Layers 10-11 are usually light shades and serve as the raw material for vein-cut products, as they have pronounced longitudinal stripes when cut against the natural bedding layer. Jura stone JuraLimestone Jura Cream is found in the "Petersbuh" quarry in layers 15 to 17. For comparison, we attach a photo of standard light and dark beige Jura stone and Jura Cream.
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🔍Directly at the quarries where raw material extraction takes place, teams work that drill the stone to a depth corresponding to the size of the block, then they break out the block using hydraulic machines. After that, the block is lifted up with the help of a tracked front loader. According to Ruf, there is no need to make horizontal cuts – the stone separates from the mass naturally.
One quarry produces between 4000 and 8000 cubic meters of Jura marble per year. Moreover, due to weather conditions, it is usually closed during the winter months of December, January, and February.
"It is important to note that this area was very calm," says Ruf. "Rock movement here was a rarity. That is why the stone in this quarry is of excellent quality. A first-class location. We will be able to develop it for another thirty years in a row."