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Celery Petrification

Stephen F. Greb
Kentucky Geological Survey


Many fossils are preserved through the process of petrification (also called mineralization). Petrification occurs when water carries minerals into the pore structures of parts of buried organisms, leaving the minerals behind. When the original organic material ultimately rots or dissolves, the minerals remain in the position of the original structures. Wood and bone are commonly fossilized in this manner. You can demonstrate how this happens by using the old capillary action demonstration; a piece of celery and dyed water. The colored water is our model for mineral-laden groundwater. When the dyed water is naturally sucked into the celery by capillary action, it mimics groundwater moving into the pore spaces of bones and plants, leaving minerals behind in the pore spaces as happens in petrification.

Grade Level : K-8

Time : 10 minutes in class or at home, and then overnight for the celery to soak up the dyed water.