1. The hard, glassy cell wall or shell of a diatom, composed of silica.
Usage: biology; technical

Examples

• Under the microscope, the frustule of the diatom displayed intricate geometric patterns.
• The frustule provides structural support and protection for the diatom cell.
• Scientists study frustule morphology to classify different diatom species.
• The silica-based frustule makes diatoms useful in industrial filtration applications.
• Each frustule is composed of two overlapping halves called valves.