Diatoms are very unique organisms that are very diverse. They also have the ability to in just aboufound at http://www.maine.gov/dep/blwq/docmonitoring/biomonitoring/sampling/algae/diatoms.htmt every ecosystem in some shape or form. But, further more they have something that no other organism has, a glass cell wall called a frustule. Its presence gives the diatoms a large amount of advantages and causes them to be a large interest to humans because of its unique beauty and because it is one of the only microorganisms that will fossilize because of it being hard tissue. The frustule is also rather complex and deals with a large amount of what the diatom is able to do.
    The frustule is made out of silicon. The diatoms obtain the silicon in the form of silicic acid this is at fairly high concentrations in waters worldwide, because silicon is one of the most prevalent elements on earth and gets consciously washed into the oceans via rivers and rain runoff. The frustule is composed of two parts or valves. They are uneven in size and fit together like a Petri dish or a pill box. The larger part is called the epitheca and the smaller part is the hypotheca. They are produced at two parts in the diatoms life cycle. The most common form is when the diatom is reproducing asexually each of the divided cells will take one of the valves as the epitheca and will secrete the hypotheca, this causes one of the diatoms involved in the division to gradually get smaller and smaller. The other part in which the cell produces the frustule during sexual reproduction and it is formed with in the auxospore. Within the auxospore both valves are produced they are produced at the maximum size that the frustule for that diatom species can be to compensate for the gradual reduction in size caused by asexual reproduction.
    The function of the frustule is rather diverse and can vary to a degree dfound at http://www.ngdc.noaa.gov/mgg/image/diatom.gifepending on species and habitat. The primary functions of the frustule though that is shared though species is rather fundamental. The functions include, but are not restricted to, providing support, protection from predation, attachment to surfaces and substrates, change the buoyancy of the organism (placement in water column), in terrestrial habitats it allows organisms to help maintain water, and it helps refract and reflect light on the inside of the organism causing a greater amount of light contact to the photosystems and increasing the effectiveness of cell to fix carbon. The frustule proves a lot more functions although not all of these apply to all species of diatom, such as organism that attach to surfaces of substrates don’t have frustules that affect the organisms buoyancy. The different attributes of the frustule are attributed to various features that are present on the diatoms.
    The features that are present on the frustules of diatoms are various and include different combinations, sizes and ordinations of pores, spines and some other features. The spines are used in varioufound at http://www.glerl.noaa.gov/seagrant/GLWL/Algae/Diatoms/Cards/Aneumastis.htmls means such as providing some protection from predation and the ability to attach to various substrates. The pores allow transport of various solutions in and out, as well as, slimes out of the cell. The pores allow the diatom to obtain some nutrients from the different sources as well as to allow them to secrete some the their extracellular polysaccharides. Some species of diatoms can also use the pores to assist in the locomotion via gliding. There are other structures the diatoms use that are on the frustule that do other structures.
 found at http://disc.sci.gsfc.nasa.gov/oceancolor/additional/science-focus/ocean-color/iron_limits.shtml
    Beyond the structure and use of the frustules diatoms other promising features that can be put to use because the majority of them are grow in open ocean and because of that it limits the growth because the lack of iron. Although, because diatoms acquisition carbon dioxide from the atmosphere, plans have been brought together to fertilize open ocean areas with iron that will facilitate diatoms in the area to grow. This causing them to talk up carbon dioxide from the atmosphere and this could reduce the carbon omissions and combat global warming.

To References

For other sites of diatoms go to http://www.ucmp.berkeley.edu/chromista/bacillariophyta.html, or http://www.indiana.edu/~diatom/diatom.html.