Assertion: diatom | /r/HasAspect | shell
Facets:
value: usually
type: TEMPORAL
Source sentences:
text: Diatoms are microscopic plants, which are in the same group as algae, and have a shell made from silicon dioxide (glass and sand are made from this).
text: What makes diatoms remarkable is they have shells made from organic compounds and silica.
text: Diatoms are microscopic single-celled algae that usually have shells that are divided into two halves.