Bolo-Agates are found near to Ciudad Chihuahua. A more detailed finding-location is not known.

“Bolos” (“Balls”) are agates that can be found in brownish Lithophysae. They have a fine-lined banding, formed by small pigmentation-spots. These little dots are usually coloured white, sometimes red. Very rare are purple colours. Those little balls are reaching sizes up to 10 cm.

Their skin is reddish and built by little perlite-grains.