All of the following statements regarding diatom are true, EXCEPT:
Diatoms are microscopic unicellular or colonial algae. It has a cell wall which is strongly impregnated with silica and contain chlorophyll and diatomin, a brown pigment. Diatoms secrets a hard silicaceous outer box like skeleton called a frustulae. They are heat and acid resistant. Ref:The Essentials of Forensic Medicine and Toxicology By Dr K S Narayan Reddy, Pages 329-30