| In the late Middle Ages massive amount of Baryt which phosphoresced when it was gently heated, were discovered in Italy. This stone was named after its place of discovery "Pietra fosforica di Bologna" (phosphorescent Bologna stone) and was of great interest to alchemists. Although the name baryte ha ... moreIn the late Middle Ages massive amount of Baryt which phosphoresced when it was gently heated, were discovered in Italy. This stone was named after its place of discovery "Pietra fosforica di Bologna" (phosphorescent Bologna stone) and was of great interest to alchemists. Although the name baryte has been assigned centuries later, it may be assumed that the Bologna stone is the first description in the literature. A portrait about this famous mineral by Peter Seroka. |
| From early tunnel construction in the 18th century to its final closure in the 1950s, the Frankenholz Mine in Germany’s Saar region was a key site of coal mining history. With ambitious shaft projects, its own cableway connection to Bexbach, and remarkable geological features – including fossil disc ... moreFrom early tunnel construction in the 18th century to its final closure in the 1950s, the Frankenholz Mine in Germany’s Saar region was a key site of coal mining history. With ambitious shaft projects, its own cableway connection to Bexbach, and remarkable geological features – including fossil discoveries and natural oil seepages – the mine reflects both the rise of industrial progress and the dangers of underground work. Gas explosions, water ingress, and tragic accidents shaped the lives of thousands of miners. Frankenholz remains a compelling reminder of a bygone mining era. |
| ... In Oberfelsberg angekommen, parkt man, der Hinweistafel folgend, in einer Seitenstraße. Dem Weg Richtung Burg laufend, erkennt man nach 10 Minuten zur Linken die ehemaligen Steinbrüche im Voltziensandstein. Die Werksteinzone steht hier mit zirka 10 m Mächtigkeit an. Hier wurde zum großen Teil de ... more... In Oberfelsberg angekommen, parkt man, der Hinweistafel folgend, in einer Seitenstraße. Dem Weg Richtung Burg laufend, erkennt man nach 10 Minuten zur Linken die ehemaligen Steinbrüche im Voltziensandstein. Die Werksteinzone steht hier mit zirka 10 m Mächtigkeit an. Hier wurde zum großen Teil der Sandstein zum Bau der Saarlouiser Festung gebrochen. Das größte Stück, das hier gebrochen wurde ... Ein Beitrag von Berthold Stein |
| ... Da offene Flammen häufig zu Explosionen von Methangas in Kohlebergwerken führten, schrieben Grubenbesitzer einen hoch dotierten Preis zur Erfindung einer explosionssicheren Lampe aus. So wurde die Davy-Lampe entwickelt. Das Geheimnis war ein simples, engmaschiges, Drahtgitter um die offene Flamm ... more... Da offene Flammen häufig zu Explosionen von Methangas in Kohlebergwerken führten, schrieben Grubenbesitzer einen hoch dotierten Preis zur Erfindung einer explosionssicheren Lampe aus. So wurde die Davy-Lampe entwickelt. Das Geheimnis war ein simples, engmaschiges, Drahtgitter um die offene Flamme. Dieses Gitter verhindert, durch Wärmeableitung, die Entzündung von Gas außerhalb der Lampe. Die Weiterentwicklung war der Einsatz von wiederaufladbaren Akkus statt ... Ein Beitrag von Peter Seroka und Wilhelm W. |
| It is not possible to write a chapter about the mineral galena without looking at the history of lead and silver to name two of the most important raw materials and materials of humanity. How long people processed galena as main ore for the production of lead is unknown. As lead inter alia used as a ... moreIt is not possible to write a chapter about the mineral galena without looking at the history of lead and silver to name two of the most important raw materials and materials of humanity. How long people processed galena as main ore for the production of lead is unknown. As lead inter alia used as an additive to various melts (e.g. to bronze and the salt-cementation process for gold extraction) one can assume that the properties of this mineral were known before 3000 BC. Other sources speak of a history of lead about 7000-9000 years BC back. |
| The term used in the plural "pyrites" has often been misused in the past or in common for marcasite, chalcopyrite, pyrrhotite and other yellow to brass-colored minerals. The word pyrite is derived from the Greek "pyrites lithos" (derived pyr = fire and lithos = stone) and describes a characteristic ... moreThe term used in the plural "pyrites" has often been misused in the past or in common for marcasite, chalcopyrite, pyrrhotite and other yellow to brass-colored minerals. The word pyrite is derived from the Greek "pyrites lithos" (derived pyr = fire and lithos = stone) and describes a characteristic of the mineral, when rubbing against steel or flint (flint) to generate sparks. In prehistoric tombs pyrite concretions and unrolled pyrite where found, which supposed to be used for lighting a fire. (Article in German) |