| 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. |
| orundsynthesen finden sich im Handel als Schmelzbirnen, in der Regel der Länge nach gespalten sind, um die inneren Spannungen im Kristall zu lösen. Sie besitzen einen kreisrunden Querschnitt. Ab und an erkennt man im Querschnitt auch eine trigonale Symmetrie. Wird das Material durch Tempern von den ... moreorundsynthesen finden sich im Handel als Schmelzbirnen, in der Regel der Länge nach gespalten sind, um die inneren Spannungen im Kristall zu lösen. Sie besitzen einen kreisrunden Querschnitt. Ab und an erkennt man im Querschnitt auch eine trigonale Symmetrie. Wird das Material durch Tempern von den Spannungen befreit, sind die Korundbirnen komplett und im Querschnitt rund oder eher abgerundet dreiseitig. Synthetische Spinellbirnen sind in der Regel komplett und besitzen einen annähernd quadratischen, aber abgerundeten Querschnitt. In der Nähe des Keimes finden selten abgerundete Oktaederflächen. Ein Beitrag von Klaus Schäfer |
| Inclusions are inside the crystal enclosed foreign materials like liquids, gases, hydrocarbons (oil, asphalt), sediment, NaCl, as well as other minerals or crystals. Inclusions can be a sort of fingerprint of the place of dicovery. Thus inclusions show us under which geologic conditions minerals had ... moreInclusions are inside the crystal enclosed foreign materials like liquids, gases, hydrocarbons (oil, asphalt), sediment, NaCl, as well as other minerals or crystals. Inclusions can be a sort of fingerprint of the place of dicovery. Thus inclusions show us under which geologic conditions minerals had formed. This allows conclusions on the place of discovery. The article deals with the different kinds of inclusions, her conditions of build, which minerals do often have inclusions and how they appear. (Full text in german) |
| Who knows Tucson with its many satellite events, has already a good taste of the Sainte-Marie-aux-Mines show. Unlike in Munich where you find the stands clear and concentrated in halls, the organizers use single fenced-off parts of the city to place the stands on the streets. Public buildings such ... moreWho knows Tucson with its many satellite events, has already a good taste of the Sainte-Marie-aux-Mines show. Unlike in Munich where you find the stands clear and concentrated in halls, the organizers use single fenced-off parts of the city to place the stands on the streets. Public buildings such as swimming pool, school and theater are transformed into smaller exhibition halls... A small showreport by Stefan Schorn (in german) |