Color:   Upper Mercer chert ranges in color from a medium gray to blue or black.

Texture:  Fine Grain

Luster: The luster may range from dull to waxy with a glassy vitreous when heat treated.

Silica Fabrics / Fossils: Fossils are commonly present including crinoid ossicles, foraminifera, fusulinid, and other Late Paleozoic marine fossils.

Patina:

Heat Treatment:  Heat treatment darkens the blues and gives a glassy vitreous sheen.

Knapping:  Upper Mercer chert can range in colors with both light and dark varieties (Figure 14). They are excellent quality and are waxy to porcellaneous. Multicolored mottling is common with dark brown to brownish yellow weathering (Figure 15). Upper Mercer is also a Pennsylvanian chert with the black samples resembling Lower Mercer cherts. Upper Mercer occurs throughout the state of Ohio with large deposits in both northern and southern Ohio.
 

 

 

 

 

 

 

 

 

 

 

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Distribution Comments:

Upper Mercer Chert is associated with the Upper Mercer Limestone of the Pottsville group  This chert occurs in large amounts and is abundant.  Primary outcroppings are located in Coshocton, Hocking. Holmes, Jackson, Mahoning, Muskingum, Perry, Portage, Stark, Sciota. Stark, Summit, Trumbull, Tuscarawas. Vinton, and Wayne Counties, Ohio.