Colorado scientists who were curious about why Castle Rock remains largely resistant to erosion have published a research paper that provides some answers. They have determined that opal is partially responsible for the notable Colorado rock’s durability.
Castle Rock is visible from several parts of central Douglas County and sits at the center of the city of Castle Rock. Dr. Hagadorn, a curator at Denver Museum of Nature & Science, describes it as an “iconic landmark.”
The study was authored by scientists from the Denver Museum of Nature & Science and states that “Castle Rock’s unique prominence and durability can be attributed to the presence of opal.”
“Generally, exposed sedimentary rocks in these areas would be prone to erosion and might crumble into rubble. The key to Castle Rock’s exceptional durability, it turns out, is that it’s held together by a unique and captivating gem mineral, opal,” Hagadorn said in a prepared statement.