Pastelite is a type of chert or jasper that is opaque. It is very hard and takes a nice polish. True to its name it can be found in several pastel hues including pink, peach, gray, orange, and a blue or violet variety that is rather elusive to casual collectors. Some is mixed or brecciated with various agate and other minerals. Also mixed in the area is opalite which is a type of common opal, usually just white or gray.

Burro Creek is one of the better known rockhound destinations in Arizona. It's fairly accessible although remote, and there is a wide range of material to be found there. Dominant is the pastelite which is strewn throughout the hills on both sides of the creek, one of the few places in western Arizona where water flows all year long. From where the road crosses the river there are collecting possibilities in all directions. To the north you can see the tailings mountain of the Bagdad mine.