Arizona Surface Chalcedony Formation

Arizona Surface Chalcedony

The Geology of Surface Chalcedony has been long misunderstood. Specimens lie on the surface of all kinds of unconsolidated sediments, not just in ‘volcanic areas.’ In fact, no one has ever reported seeing chalcedony form in a volcanic setting on land. Of course they wouldn’t, because chalcedony is a form of quartz that grows in a hypretherm (under deep hot water).  This is why they do not appear to have a surface origin. The rounding was caused by endoerosion; movement in underground aquifers. They were ejected onto the surface near the end of the Deluge, when the final frictional heating occurred, as continental plates moved back into place. Learn more in Chapter 8 of the UM.