WE SHIP! The AEAA is very proud to present this large and impressive The AEAA is extremely proud to showcase this dynamically large & brilliantly handsome rich Amber / topaz Quartzite sedimentary Geode most likely from the Warsaw Formation in the central USA (Iowa, Illinois). Our church steeple standing erect example is special in this size, and it is difficult for photos to do justice to this incredible mineral formation, most likely around a million years old. Our fantastic Geode stands 14 x 8 x 20 inches tall and weighs in at a hefty 61#. This heirloom is from the living estate of Ailene & Buddy Ford, noted lifelong collectors / dealers of valuable antiques. xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx. Geodes are geological secondary structures which occur in certain sedimentary and volcanic rocks. They are themselves of sedimentary origin formed by chemical precipitation. Geodes are essentially hollow, vaguely spheroid to oblate masses of mineral matter that form via either of two processes:by the filling of vesicles (gas bubbles) in volcanic to sub-volcanic rocks by minerals deposited from hydro-thermal fluids or by the dissolution of sedimentary nodules or concretions (that were deposited syngenetically within the rock formations in which they are found). They are also partial filled by the same or other minerals precipitated from diagenetic water, groundwater or hydro-thermal fluids. Geodes are special in that they were formed as early, rounded, structures within the surrounding rock and are often removed intact. Geodes commonly have a chalcedony (cryptocrystalline quartz) shell lined internally by various minerals, often as crystals, particularly calcite, pyrite, kaolinite, sphalerite, millerite, barite, celestite, dolomite, limonite, smithsonite, opal, chalcedony and macrocrystalline quartz, which is by far the most common and abundant mineral found in geodes. Geodes are found mostly in basaltic lavas and limestones. The Warsaw Formation in the Keokuk region near the area where Missouri, Iowa, and Illinois join contains abundant geodes. Which minerals end up as crystals in a geode varies by location and conditions such as temperature, acidity, and the type of rock the geode forms from. For instance, quartz crystals are most common in igneous geodes. Silica is more common in geodes that form in sediment.Many other minerals can be found inside geodes, too. Geodes found in Brazilian quarries host soapstone and several kinds of quartz, while geodes from central Spain are filled with gold-laced hematite (the stone they use to make that magnetic jewelry). Many of these minerals, in addition to others including dolomite, calcite, and Iron Pyrite, (fools gold) have been found among the geodes in America’s Midwest.Such mineral crystallization forges a rock fit to cut in half, polish and use as bookends. Not all geodes, however, are the perfect size to corral books. Some are small enough to fit in the palm of your hand or to catch the light while perched on your windowsill. At the other end of the scale, the largest gypsum crystals, from a cave in Naica, Mexico, have grown up to 36 feet long.But enormous geodes are not unique to Mexico—according to Harlow, the geodes in the Paraná Basin of South America are also large enough for people to hide in.

VG condition, with an internal fissure. XA MM - 15