| Siderit war neben Hämatit, Limonit, Goethit und Magnetit immer eines der wichtigsten Eisenerze, wobei es kaum nachvollziehbar ist, welches dieser spezifischen Minerale zu einer bestimmten Zeit verhüttet wurde - ausgenommen, die Überreste urgeschichtlicher bis antiker und mittelalterlicher Eisengewin ... moreSiderit war neben Hämatit, Limonit, Goethit und Magnetit immer eines der wichtigsten Eisenerze, wobei es kaum nachvollziehbar ist, welches dieser spezifischen Minerale zu einer bestimmten Zeit verhüttet wurde - ausgenommen, die Überreste urgeschichtlicher bis antiker und mittelalterlicher Eisengewinnung sind eng an ein spezifisches Siderit-Vorkommen gebunden. Im Grunde genommen gibt es für Siderit keine eigene Geschichte, es sei denn, man erforscht sie mit einem interdisziplinären Ansatz im Zusammenspiel von Ethnologen, Montanhistorikern, Geologen und Ingenieuren. Ein Mineralienportrait geschrieben von Peter Seroka |
| The metal extraction by ore leaching (mostly copper) was about 1,000 years BC. known in the Mediterranean, but there are also barely no written records. The in the Middle Ages and in the following Renaissance well-known different procedures were first described in detail by Georg Agricola 1556 in hi ... moreThe metal extraction by ore leaching (mostly copper) was about 1,000 years BC. known in the Mediterranean, but there are also barely no written records. The in the Middle Ages and in the following Renaissance well-known different procedures were first described in detail by Georg Agricola 1556 in his book "De Re Metallica Libri XII". A contribution by Peter Seroka |
| Olivine is not a separate mineral, but a member belonging to the forsterite-fayalite mixing series. Olivine belongs to the olivin-groupe whose end-members are calcio-olivine and tephroite. Forsterite is a magnesium silicate; fayalite an iron silicate. If commonly is spoken of olivine, it is usually ... moreOlivine is not a separate mineral, but a member belonging to the forsterite-fayalite mixing series. Olivine belongs to the olivin-groupe whose end-members are calcio-olivine and tephroite. Forsterite is a magnesium silicate; fayalite an iron silicate. If commonly is spoken of olivine, it is usually a more or less iron-rich forsterite. The color of olivine is generally yellowish green, olive green to black. You will find much more interesting details in our portrait about this common mineral series. Written and investigated by Peter Seroka. (Article in german) |
| Actually, this is a picturesque place in a well-kept forest. Nevertheless, in the past, evil itself is said to have preached to the damned here from a large, solitary, towering rock spur. Today, the term Devil's Pulpit inspires one to play with associations, as do the drawings of agates found here. ... moreActually, this is a picturesque place in a well-kept forest. Nevertheless, in the past, evil itself is said to have preached to the damned here from a large, solitary, towering rock spur. Today, the term Devil's Pulpit inspires one to play with associations, as do the drawings of agates found here. Their fantastic outlines, coupled with the unusual shape of the secondary rock, evoke images in the viewer that he would not have suspected in a stone. And on the devil's pulpit no longer an evil demon is waiting for the agate collector, but other executive powers threatening with purgatory... a contribution by Klaus Schäfer and others (in german) |