Plasti-what? Plastiglomerate.
Plastic debris on Kamilo Beach
Hawaii’s Kamilo Beach is known for its large accumulation of plastic debris washed ashore by Pacific currents. Photo by Kim De Wolff.

Human trash enters the Earth’s rock record

Meet plastiglomerate. Discovered along Hawaii’s Kamilo Beach, plastiglomerate is composed of sand, hardened lava, shells, and plastic. It is an artificial stone formed through campfire burning of plastic trash into beach sediment and lava fragments. The melted plastic cements the various components together, which cool to form a solid structure.


The discovery of plastiglomerate marks a disturbing record of environmental pollution, ensuring that humanity’s trash will remain within Earth’s rock record long into the future.


Temporarily removed from the Hall of Minerals, Earth and Space.