Ancient Insect Preserved Inside Iridescent Opal
via The Verge
Some trees exude a sticky sap that can immobilize bugs, leaves, seeds, and other ancient life forms. If these ensnared creatures are buried in the right sedimentary conditions, the sap transforms into a soft material called copal. Over millions of years of underground heat and pressure, copal polymerizes into hardened amber. After this amber sample preserved the insect, [Brian] Berger suggests that it became “opalized.”