Color:  Coeymans Chert ranges in color from a brownish green to a bluish black or black.  Cloudy patches of fine pyrite and quartz may be present.

Texture:  Medium grain

Luster: Waxy

Translucency: 

Silica Fabrics / Fossils: Highly fossiliferous including crinoids and pentamerid bachiopods.

Patina:

Heat Treatment:

Knapping:
 

 

 

 

 

 

 

 

 

 

 

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Distribution Comments:

Coeymans Chert is associated with the Coeymans Limestone Formation (New Creek Limestone Formation), Helderberg Group of New York, New Jersey, Maryland, and Virginia.  Primary outcroppings are found from Orange County, New York into New Jersey, throughout Maryland and as far south as Clifton Forge, Virginia.  Coeymans Limestone Formation also called the Ravena Limestone Formation in the Hudson Valley.