Color:  Color ranges from creamy white or whitish gray to pale blue or yellowish brown with yellow and brown streaking

Texture: Fine grain

Luster:

Translucency:

Silica Fabrics / Fossils: includes brachiopods, horn coral, bryozoa, sponge spicules, and crinoid columns.

Patina:

Heat Treatment:  Heat treatment produces colors of grays, pinks, and tans with occasional bands of reds and purples.  Heat treatment increases the luster.

Knapping:  Knapping non-heat treated material is difficult, but increases knappability when heat treated. 
 

 

 

 

 

 

 

 

 

 

 

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Distribution Comments:

Keokuk Chert is associated with the Keokuk Member of the Burlington Limestone Formation of Illinois, Missouri, and southeastern Iowa.  Primary outcroppings are found in Hancock County, Illinois.