This is not a stone
Marvellous creations called plastiglomerate are a newly emerging phenomenon containing volcanic rock, coral pieces and plastic. They form along shorelines where organic debris agglutinate by melted plastic created during campfire burning. The Artist Tony Cho collected these colorful rocks for an exhibition at "Mmuseumm," NY. Cho found them in Mallipo, Corea, where the largest offshore oil spill in Korean history occurred after a tanker accident in 2007.
Marc Baumann “Plastische Kunst”, SZ Magazin, 10.07.2020, p.16-19, photo: Leonie Hugendubel.