| 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. |
| ... Over time, rocks weather due to the influence of wind, water, ice, and daily and seasonal temperature differences. These weathering products form then short the pedosphere (the ground), go into solution in water (chemistry), are transported as dust, and similar processes. Long term, but they rea ... more... Over time, rocks weather due to the influence of wind, water, ice, and daily and seasonal temperature differences. These weathering products form then short the pedosphere (the ground), go into solution in water (chemistry), are transported as dust, and similar processes. Long term, but they rearrange stable, lithify and form sedimentary rocks, are transported into the deep, and after transformation (metamorphosis) reveal pushed back ... An article by Peter Seroka, written in German |
| In 1978 the US - American geologist Walter Alvarez gained a narrow pattern red clay in the Italian Apennines and certain age these samples to approximately 65 million years , ie at the end of the Cretaceous period and the beginning of the Tertiary period. This very thin lime- clay layer lies between ... moreIn 1978 the US - American geologist Walter Alvarez gained a narrow pattern red clay in the Italian Apennines and certain age these samples to approximately 65 million years , ie at the end of the Cretaceous period and the beginning of the Tertiary period. This very thin lime- clay layer lies between two calcareous sediments and showed a different fossil record , which to a mass extinction ( faunal ) hinted . While further analysis Alvarez noted a high iridium concentrations; a typical ... An article by Peter Seroka (written in german) |
| ... Das seit 1958 blei- und zinkerzfördernde Bergwerk Daoping ist unter Sammlern durch hervorragende, wenn nicht sogar weltbeste Pyromorphitstufen bekannt geworden. Die am Haiyang-Shan-Berg gelegene Mine wurde 2003 mit der nahgelegenen Yangshuo Mine unterirdisch verbunden. Während die Daoping Mine i ... more... Das seit 1958 blei- und zinkerzfördernde Bergwerk Daoping ist unter Sammlern durch hervorragende, wenn nicht sogar weltbeste Pyromorphitstufen bekannt geworden. Die am Haiyang-Shan-Berg gelegene Mine wurde 2003 mit der nahgelegenen Yangshuo Mine unterirdisch verbunden. Während die Daoping Mine im Bezirk Gongcheng liegt, ist die Yangshuo-Grube Teil des Yangshuo-Bezirkes. Beide Gruben bauen denselben Erzkörper ab. Es ist daher nicht verwunderlich das gute Pyromorphitfunde in beiden Gruben gemacht wurden. Die bisher besten Pyromorphite ... Ein Artikel von René Gervers mit Beitrag von Roland Noack |