Color: John's Valley Chert ranges in color from a bluish black to a gray or chocolate brown.  It is a variegated or marbled chert.

Texture:

Luster:

Translucency: 

Silica Fabrics / Fossils:

Patina:

Heat Treatment:  Heat treatment increases the knappability of the chert at low temperatures, but explodes at temperatures above 190 degrees.

Knapping: 

 

 

 

 

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Distribution Comments:

  Johns Valley Chert is associated with the John's Valley Shale Formation of the Ouachita Mountains of Arkansas and Oklahoma.  Named for Johns Valley in Pushmataha County Oklahoma with primary exposures in the center of the Tuskahoma syncline.