The letters came from everywhere—Verona, Italy; Littleton, Colorado; Oakland, California; Augsburg Germany; Sherrodsville, Ohio; Springfield, Massachusetts; Bronx, New York. They were written by children, teenagers, and adults, and while some were just a few words, others filled pages with detailed life stories. But they all shared the same sentiment: Please take back the rocks we stole. We’re sorry; we shouldn’t have done it.
In 2011, during a chance trip to Petrified Forest National Park in northeastern Arizona, a couple of these letters caught the eye of artist and educator Ryan Thompson. At the time, the Rainbow Forest Museum included a small exhibit of correspondence sent to the park by people who’d surreptitiously taken petrified wood during their visit, and later felt guilty enough to return it. A steady stream of these so-called “conscience letters” (nobody’s quite sure who coined the phrase) have been archived by the national park’s staff since 1934, albeit inconsistently. Today, the park has more than 1,200 conscience letters in its archive.
Fascinated that the park had even saved these letters, Thompson connected with the park’s museum curator, Matthew Smith, to learn more about the archive’s history. Thompson’s curiosity gained him access to many of the archived letters, and in 2014, along with Phil Orr, he published the book Bad Luck, Hot Rocks, chronicling a portion of the conscience letters and some of the the rocks they accompanied.
Typically, these conscience letters indicate remorse for the theft and attribute bouts of misfortune to the ill-gotten petrified wood. Writers who describe their troubled lives often hope that by returning the stolen goods, their bad luck will disappear as well. So how did rocks from the Petrified Forest become tied to calamity and misfortune?
Arizona’s petrified forests formed nearly 200 million years ago during the late Triassic Period, when fallen logs washed into a river system and were buried by sediment and other debris, isolating the logs from oxygen and slowing the decay process over centuries. The porous wood slowly absorbed various minerals, including silica from volcanic ash, which crystallized over thousands of years, replacing the organic material as it broke down. Eventually, the logs and branches were transformed into colorful pieces of nearly solid quartz.