Credits/links for images above, from top to bottom:
1) Image: Argonne National Laboratory at Flickr
2) Image: Kenneth M. Bart (many more of his gorgeous microscopy images)
3) Image: via
4) Image: via
5) Image: Stinging Eyes at Flickr
6) Image: via
7) Image: via
8) Image: via
9) Image: via
10) Image: Piotr Rotkiewicz (more of his outrageous beauties)
11) Image: via
From Greek diatomos = cut in two. Named because they typically appear to be cut in half.
Diatoms are microscopic algae composed of separate halves, with delicate siliceous cell walls. They're usually single-celled organisms, though some live colonially. They inhabit fresh and salt waters and are among the most abundant of all phytoplankton.
Below are a few examples of diatom art—practiced since Victorian times—of arranging diatoms pleasingly. Thanks, freaky Victorians! Thanks, microscopes!
Credits/links for images above, from top to bottom
i) Image: Klaus D. Kemp
ii) Image: via
iv) Image: via
v) Image: Montana Diatoms