Definition
A diatom is a single-celled alga known for its distinctive silica cell wall, called a frustule. This frustule is made of two overlapping halves, like a tiny pillbox π. Diatoms are found in oceans, lakes, and soils, playing a vital role in the carbon cycle. They're essentially microscopic glass houses floating in water π . They are a major type of phytoplankton, converting sunlight into energy.