Silicate lava (black) and metallic lava (silver) remained largely separate as they flowed from the lava furnace. Denser and faster flowing metallic lava traveled underneath slower moving and less dense silicate lava and remained unmixed as both cooled. Credit: Soldati et al., 2021, https://doi.org/10.1038/s41467-021-21582-w, CC BY 4.0