| 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) |
| ... As already mentioned elsewhere, mining in Ilmenau dates back to the year 1200. In 1216, Count Poppo v. Henneberg was enfeoffed with the Bergregal by Friedrich den II. At that time one had discovered mineralised steep copper slate near Roda and on the Sturmheide. Presumably, individual miners had ... more... As already mentioned elsewhere, mining in Ilmenau dates back to the year 1200. In 1216, Count Poppo v. Henneberg was enfeoffed with the Bergregal by Friedrich den II. At that time one had discovered mineralised steep copper slate near Roda and on the Sturmheide. Presumably, individual miners had been enfeoffed, who extracted copper slate and sandstone in accordance with the mining freedom. This is generally regarded as the beginning of the first main period of Ilmenau mining. The ore was mined in small open pits to a maximum depth of 50m. ... A Contribution of {:10697:} |
| People have always been fascinated by precious stones because of their lustre. But not only polished gems shine. Each raw mineral has, such as mica flakes in the river sand show, its very special characteristic luster. Gloss isn't simply measurable. It is usually described by comparison with objects ... morePeople have always been fascinated by precious stones because of their lustre. But not only polished gems shine. Each raw mineral has, such as mica flakes in the river sand show, its very special characteristic luster. Gloss isn't simply measurable. It is usually described by comparison with objects of everyday life ... (in german) |