Color: Joliet chert ranges from white to gray

Texture: Medium to fine grain

Luster: Dull

Silica Fabrics / Fossils:  Sponge spicules, brachiopods, brazoans, corals, and crinoid columnals

Patina:

Heat Treatment:  Heat treatment brings a slight pinkish hue and increases the luster.

Knapping: 

Note:  It is difficult to distinguish Elwood Chert from Joliet Chert outside the source.  Many publications treat both cherts as the same and hyphenate the name Elwood-Joliet Chert.  There are many overlapping characteristics between Burlington, Elwood, and Jolie cherts making identification between these cherts difficult.
 

 

 

 

 

 

 

 

 

 

 

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Distribution Comments:

 Joliet Chert is associated with the Joliet Formation which rests on the Elwood Formation.  Named for outcroppings located in Joliet Il.  Primary outcroppings occur in northeastern Illinois and into Wisconsin and Iowa.