Agate lava geode. Close-up of the polished face of a section through an agate-containing geode from volcanic deposits. Agate is an aggregate of different forms of silica (SiO2) within a geode. Geodes form when silica precipitates from liquid onto the inside surface of empty pockets in a host rock. Here the host rock is rhyolitic lava that has been filled with blue-white chalcedony (non-crystalline silica),and haematite (iron oxide,red). This specimen was found in the Esterel Mountains,France | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Wiersma, Dirk |
Bildgröße: | 4148 px × 4239 px |
Modell-Rechte: | nicht erforderlich |
Restrictions: | - |