Color:  Dean Lake Chert ranges from a blackish gray to a tannish gray or bluish gray / black.  

Texture:

Luster: Dull

Translucency: 

Silica Fabrics / Fossils: Fossiliferous including crinoid stems, brachiopods

Patina:

Heat Treatment: 

Knapping: 
 

 

 

 

 

 

 

 

 

 

 

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Distribution Comments:

Dean Lake Chert is associated with the Dean Lake Member of the Madison Limestone Formation northwestern Montana.  Primarily occurs as nodules occurring around Dean Lake in the Pentagon Mountains of Montana.