“... One of the most popular collecting areas in Arizona since many years is the area around the Burro Creek , located in northwest Arizona on Highway 93. The today as " Recreation Area " designated area is not only the home of agate, but also jasper, opal and chalcedony , sometimes alll together in one specimen. Both the yellowish white opal and the brown jasper are sometimes traversed by intense black dendrites , which provides mainly for the manufacture of cabochons excellent opportunities. The size of the specimen is considerable and can reach up to 30 cm in diameter. Noteworthy of this finding location is an extremely violet jasper , which also occurs in large rough chunks...”.
wrotes Joahnn Zenz in his book “agates I”, 2005, Bode publishing house