This is a nice Quartz geode from Alexandria, Missouri. It was collected from a geode-bearing layer of shale just outside of town in Clark County in what folks visiting the "Keokuk Region" refer to as geode country. Geodes from this area are known for their high quality and the diversity of minerals, crystals, and their combinations that may be found therein. This region is located in the Tri-State area of Missouri, Illinois, and Iowa. Geodes may be found within a 60 mile radius of the city of Keokuk, Iowa which is where these geodes derive their name. Wherever a river, stream, or outcrop of geode-bearing rock is exposed within this region, you are very likely to discover a treasure trove of geodes.

This geode is composed of an outer shell of Chalcedony that has been lined with Quartz crystals. Sitting on top of the Quartz is a large crystal of Calcite. A smaller Calcite crystal can be seen next to the large crystal in one half.  The white lacy mineral is Aragonite, with the tiny pepper like crystals being Pyrite. The large Calcite crystal was split down the middle during opening and gives you a look inside this type of mineral and the crystal it formed. Cleavage planes are easily seen as well as the crystal faces on the outside. A light citrine-colored tint can be seen on some of the quartz crystals, likely due to the weathering of the Pyrite crystals peppering the Quartz. This geode is a Mineralogy lesson in and of itself, and would make an excellent visual study aid for any Earth Science or Geology related course. It will also make a nice addition to any collection.

It is slightly larger than a baseball in size.

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