Color:  Winterset Chert is primarily homogenous, but may range to mottled or layered with colors ranging from a light to dark gray or brownish gray which tends to be opaque.  Commonly has a "zebra striped" appearance.

Texture:  Very fine grain

Luster: Dull to waxy

Silica Fabrics / Fossils: Small fusilinids and colonies of calcarious algae.  In variation #6 and #7 abundant fusilinids and small brachiopods are present.   

Patina: Pale brown with occasional grayish bands

Heat Treatment:  Heat treatment produces color changes from a very dark gray to a weak red.

Knapping: 

Note:  Outcroppings often occur in the same areas as Bethany Falls Chert making identification of darker varieties of Winterset Chert and Bethany Falls chert difficult.

 

 

 

 

 

 

 

 

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Distribution Comments:

Winterset Chert is associated with the Winterset Limestone Member of the Dennis Limestone Formation, Kansas City Group.  Primary outcroppings are in the Kansas City area.  Outcroppings also occur in Adair, Decatur, and Madison counties, Iowa, Platte, Jackson, Clay, and Ray counties, Missouri, and southern Miami County, Kansas