Color:  The color is primarily a mottled or banded white to light gray or light blue.  Numerous fossils are present giving a brown or black speckled appearance.  Vugs or quartz inclusions are commonly present. 

Texture: Medium grain

Luster: Dull to waxy

Silica Fabrics / Fossils: Larger fossils are usually present.  Other fossils include brachiopods, crinoids, bryozoans, and sponges.

Patina:

Heat Treatment:  Heat treatment is primarily used which produces shades of pinks and reds, often variegated over the surface and increases the luster.

Knapping: 

 

 

 

 

 

 

 

 

 

 

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Distribution Comments:

Cedarville-Guelph Chert is associated with the Niagara Group, Cedarville-Guelph formation of western Ohio and into Michigan and Indiana.  Primary outcroppings are found in Greene, Logan, Clark, and Champaign Counties, Ohio.  Also found in Hardin, Marion, Seneca, and Wyandot Counties. counties, Ohio.  Cedarville - Guelph Chert is a local chert and is abundant.