Hunting for Keokuk Geodes in Nauvoo

This past month has been a blast collecting geodes.  A typical trip lasts about one hour and nets about 20 pounds of geodes.  This is about 3 milk jugs full.  The geodes vary in size from a hazel nut (1") up to a small cantelope (5").  At a later time I crack open the bigger ones with a chisel and three pound sledge hammer.   I currently have about 350 geodes of which 200 are small ones that Pam Olsen wants to use at her Cub Scout Day Camp in Medford next summer.

A geode is a hollow spherical rock.  They can be distinguished from the other rocks in the stream bed in four ways.  First they are almost always round whereas other rocks have sharp edges.  Secondly the outside is rough like a cantelope never smooth.  Thirdly since it is hollow it is lighter than similar sized rocks.  Lastly it is usually the color of a cantelope.  When I'm in doubt I'll throw the rock against another bigger one in the stream bed to break it open.  Most of the time it is only a rock and bounces but I've occasionally ruined some beautiful geodes this way because it usually shatters them.

The outer rind of a geode is always a one centimeter crust of chalcedony (silicon dioxide) that is grayish.  The inter layer is quartz crystals.  If the entire center is filled it is called a nodule and is less prized.  The inter ring can be calcite (white powder like crystals) or occasionally a blue gray layer of semi precious chalcedony bubbles.  There are also yellow and orange formations that are iron based.

This Nauvoo area is famous for an abundance of geodes.  The rock hounds call them Keokuk Geodes and they exist in a 50 mile radius around the town of Keokuk, Iowa which is on the Mississippi river.  I have found most of my geodes in Joseph's Creek which is on the northern edge of Nauvoo, Illinois.  The stream is about three miles long and runs through Joseph Smith's farm site.  Just before the stream empties into the Mississippi it runs by the limestone quarry that was used as the source of the Nauvoo Temple stones in 1840.

The drought this year has left the stream bed dry which is one of the reasons the "pickings" have been so good.  In the LDS Church movie "Legacy" there is a scene where a wagon slips over a stream bank and turns over.  This is where I found the geodes in Joseph's Creek!

The geodes are in a bed of shale called the Lower Warsaw Formation.  When a stream cuts into the ground it exposes this formation.  The geodes are interpersed in the shale like bubbles.  When the geodes are exposed they fall into the stream and lay there for decades waiting for a rock hound to pick them up.

If a person is too lazy to find the geodes in a stream bed, then e-bay is a good alternative.  The unopened geodes cost about $3 per pound.  A three inch diameter geode weighs about one pound.  Opened geodes cost about twice as much.  My favorite geodes contain "dog tooth" crystals which are clear angular crystals with a sharp end that looks like a dog's canines.

I'm hauling about 150 pounds of the geodes home in November.  Drop by our house in Corvallis if you would like one of the small 2" ones as a gift.  We'll have you put on the safety glasses and see what surprise is waiting inside.