diatom
/ˈdaɪəˌtɑm/
noun
- A very small, one-celled alga that lives in water and has a hard, glassy shell. Diatoms are important for producing oxygen and are used in products like toothpaste and filters.
- Scientists study diatom fossils in lake mud to learn about past climates.
- Under a microscope, the diatom looks like a tiny glass box with intricate patterns.
- Many toothpastes contain crushed diatom shells to help scrub away plaque.