A generous (and much needed) rain didn’t deter a small, but eager group of students from getting to know the stories of some of their own ‘pet rocks’ collected over the years in September’s ‘Best of Pet Rock Show’ class. Long-time SFI instructor and geologist John Roth led the class in an introduction to on-the-ground rock ID, utilizing both students’ own rock collections and common examples from the Illinois Valley.

SFI’s volunteer course host, Kaci Elder, reported back on her class experience: “It had rained hard Saturday morning, but as we began the day by driving up Illinois River Road to spot rocks, the rain ceased as soon as we stepped out of our cars. We spent about 2 hours identifying rocks along the road, then returned to SFI and hiked to the creek for more identification. John helped identify rocks the students brought from home, which resulted in great storytelling of rocks purchased, found, and gifted. For the final portion of the class, we slowly walked the SFI rock path as John gently quizzed us about the rocks. He knows so much and was generous in sharing his knowledge and experience.”

Student Gary uses a small magnet to test rock characteristics. Photo by Kaci Elder
John describing specimens along the rock path.
Learning together.
Photos by Kaci Elder

When asked about any ‘magic moments’ experienced during the class, students responded –


The "realization of how much 'life' is within rocks. Infinite variations along the igneous, sedimentary, and metamorphic continua."

"I was born in Fresno, California and now live in O'Brien, Oregon. I learned that my present home used to be the northern tip of the Central Valley, where Fresno lies. What a surprise geological connection between past and present!"

John professed at the beginning of class that his goal was to convince folks that “if you adjust your time scale a little, geology is actually very dynamic and exciting.” Based on the responses above, I think that aim was achieved.