Animal, vegetable, or mineral?
Though it looks like an enormous honeycomb, this specimen wasn’t made by bees or any animal. In fact, it was never alive.
This mineral structure is the remains of a naturally-forming rock called a septarian concretion.
What’s it made of? Water seeped through cracks in the concretion, depositing silica in the form of quartz. The quartz crystals formed walls...
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