They Turned To Stone by Julian May, 7th Scholastic paperback printing, TJ1201, 1971, 31 pages. Illustrated by Jean Zallinger.
DESCRIPTION:“When you see a stone, pick it up. Look at the stone. Look at it very closely. Maybe your stone is a fossil. Maybe- millions of years ago- your stone was a living thing. Maybe it was a plant- or a fish- or part of a dinosaur. This book tells you about fossils.” (from the back cover)