The Rio Sao Fransisco is depositing agates in its sediments at several places in Bahia. These agates are strongly stressed by transport and wheathering.

These facts changed the appearance of the nodules into an unusual look for brazilian agates. The nodules are showing structural similarities to the North American Fairburn agates from the outside. Cut and polished, they show strong similarities with agates from Algeria. in colors and pattern. However many of the agates are presenting a gravitational banding (“waterlevel-type”), which is atypical for the discovery sites mentioned above.

The pebbles Rubble offered so far on the collectors market do not exceed a size of 10 cm.