frustule

/ˈfrʌstʃuːl/
noun
  1. The hard, silica-based cell wall or shell of a diatom (a type of microscopic algae), typically consisting of two overlapping halves.
    • The frustule remains intact long after the diatom dies, preserving its shape in sediment.
    • Scientists study the patterns on a frustule to identify different species of diatoms.
    • Under the microscope, the diatom's frustule looked like a tiny glass box.
Synonyms