Color:  Cumbres Pass chert  is mottled and ranges in color from a white gray to tan or brown and olive green.  Vugs and inclusion may be present, both open and quartz and chalcedony filled..

Texture: Fine grain

Luster: Waxy to vitreous

Translucency:  Opaque

Silica Fabrics / Fossils: Absent, however may have a oolitic appearance due to air bubbles in the material that was flattened by compression and then filled by quartz.

Patina:

Heat Treatment:  Heat treatment produces hues of pink and burgundy.

Knapping: 
 

 

 

 

 

 

 

 

 

 

 

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Distribution Comments:

Cumbres Pass Chert is thought to be associated with tuff deposits within the San Juan Volcanic field.  Primary sources in the Cumbres Pass in the San Juan Mountains on the border of Colorado and New Mexico.  Cobbles are found throughout the Rio Grande River gravels of the San Luis Valley.