Sheath folded quartz vein, Santa Catalina Mountains, Tucson, Arizona

Whereabouts

A neighbor came over to our house one morning and handed this to me (in ~1994).  She found it while looking for golf balls along a desert course.  It obviously had been transported downslope from the Santa Catalina Mountains.  She thought it might be a fossil bone.  I ‘pronounced’ it a sheath fold, and hope that I am right.  It is not often that you can hold a sheath fold, and most of its puzzling geometry, in your hand.

Age & Formation
Unknown.