Agate - Fortification with black and white banding.

 Agate, partial round, fortification-type, black and white banding with open center all the way to the back.

Front face is polished.
Miniature 1.85 inches wide x 1.5 in tall.
Fluoresces green under shortwave. 
New Mexico, USA.

Legacy: K. Schilling Collection 1988.

John and Judy Washburn Collection 2006.