Color:  Elwood Chert ranges from white to gray

Texture: Medium to fine grain

Luster: Dull

Silica Fabrics / Fossils:  Brachiopods are common, also sponge spicules, brachiopods, brazoans, corals, and crinoid columnals may be present.

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:

Elwood Chert is associated with the Elwood Formation below the Joliet Formation.  Named for outcroppings found in Elwood Il. Primary outcroppings occur in northeastern Illinois and into Wisconsin and Iowa.