If you put chalk under a powerful microscope—white cliffs of Dover type chalk, not the modern blackboard variety—you will see something like this Because it's not just a rock. It's an accumulation of ancient skeletons: the armored husks of single-celled, ocean-dwelling plankton
affectionateclass on July 27th, 2018 at 18:37 UTC »
cant decide if this is the most interesting thing i've ever seen or the thing that's gonna invade my nightmares forever
WallyJade on July 27th, 2018 at 19:33 UTC »
Is each "sphere" a plankton, or is each oval-shaped "panel" on the spheres the plankton?
jayd00b on July 27th, 2018 at 19:59 UTC »
For anyone interested these are Coccolithophores. They are a type of diatom, a subclass of silica-based microalgae.
Source: Underwater acoustics researcher who got sucked into this bullshit sediment characterization project
EDIT: They are not diatoms. See below.