Color:  Lower Nachusa Chert ranges from a slightly mottled white and gray.

Texture:  Medium to fine grain

Luster:

Silica Fabrics / Fossils:

Patina:

Heat Treatment: 

Knapping: 
 

 

 

 

 

 

 

 

 

 

 

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Distribution Comments:

Lower Nachusa Chert is associated with the Nachusa Formation of Illinois.  Primary outcroppings occur in LaSalle and Lee counties, Illinois.  Everett Chert is associated with the upper levels of the Nachusa Formation.  The middle level, Elm Member, has occuring chert, but the lower level,  Eldeno member is absent of chert.