Students hold a surprising number of misconceptions about how rocks form. This study analyzes narrative essays- stories of rock formation - written by pre-service elementary
school teachers. Most students had completed a
college-level course in earth science, yet expressed startling misconceptions, including pebbles that grow, human involvement in rock formation, and sedimentary rocks forming as puddles dry up. These misconceptions arise
from deeply held but largely unexamined beliefs, called here conceptual prisms. Conceptual prisms result from the interaction of the student’s world view and personal experiences. These beliefs are largely unaffected by traditional science instruction. Instead, students experience instruction refracted through their conceptual prisms, resulting in a spectrum of student ideas about geology. Instruction that does not explicitly address misconceptions and the underlying conceptual prisms is likely to be ineffective.