Keokuk Geode Samples

The following pictures are all typical examples of the minerals encountered in the 1.5 and 2 inch diameter Keokuk geodes.  A percentage estimation of the linings is also provided.  Please note that the actual percentages WILL vary from shipment to shipment, and are provided just as a guide of what is commonly encountered and what past customers have told us from their experiences.

We also encourage the use of this page for those who have/will purchase these geodes for mineral identification.

Geode Linings 

        Clear Quartz Crystals

        Calcite Crystals

  Quartz Crystals with Iron

                Chalcedony

        Frequency:  60%

          Frequency:  20%

Frequency:  10%

                 Frequency:  10%

Secondary Mineral Inclusions

Many of these Keokuk geodes have secondary minerals.  Approximately half (50%) contain more than just the linings above.  The frequency of secondary minerals varies widely, but the minerals at the top pictured below are more frequent than the ones at the bottom.  We do not guarantee what secondary minerals you will get or how many geodes will have any of the following.  The distribution is totally random and not predictable!

 

          CALCITE  (large secondary clear/opaque crystal, maybe several crystals)

 

 

      DOLOMITE  (dark brown saddle shaped crystal, usually in clusters)

 

 

      DOLOMITE (lighter orange saddle shaped crystal, usually in clusters)

 

               KAOLINITE (white powdery mineral - can usually be washed out of the geode if not wanted)

 

 

 

 

 

   MARCASITE (blades, usually with protrusions)

 

      PYRITE (mostly rods, but sometimes small shiny cubic crystals)

 

BARITE (blue tabular, either individual or clusters)

 

         BARITE (blue tabular, either individual or clusters)

 

 

 

 

 

Brown CALCITE,  some phantoms

 

SPHALERITE (black crystals, always associated with white kaolinite, usually in calcite lined geodes).  Sphalerites with an orange mineral is most likely smithsonite.

 

DEWDROP DIAMOND quartz variety geode - has white chalcedony with smaller clear/smoky quartz on top of chalcedony - dewdrops are scattered on chalcedony, not a complete lining

 

BARITE (yellow tabular crystals less frequent than blue crystals pictured above in the smaller geodes)