Item# 1A GI-O11160003
Idar-Oberstein Crystal Agate Geode half from Setz Quarry, Germany (polished) ex; Joan Cook collection
Polished half, Idar-Oberstein Crystal Agate Geode
Agates around Idar-Oberstein are found in the so called Rotliegend, in basalt flows from the Permian age. These flows produce a lot of different types of agates in very different places. The best finds one can make in the quarries around Idar-Oberstein. Some are really famous like the Setz Quarry, the Vollmersbach Quarry and the Bernhardt Quarry. Also the quarry near Freisen is famous for it’s agates and smokey quartz with goethite crystals. Unfortunately these quarries are closed now.
These specimens can be found in the basalt cliffs of the area, pieces of usable size are now extremely rare. Amygdules form when calcite, quartz, chlorite or one of the zeolites, which are deposited by having minerals "wash" through the pores in the the vesicular cavities (created by expanding gas bubbles in volcanic lava) are filled with a secondary mineral such as calcite, quartz, chlorite or one of the zeolites, which are deposited by having minerals "wash" through the pores in the outside, making some amygdules concentrically layered.
This geode weighs 5.3 oz or 0.34 lb (153g) and measures 2.7 x 2.2 x 1.3 inches (6.9 x 5.8 x 3.3cm)