Diatoms are tiny single-celled organisms that make up diatomaceous earth. They were first discovered in 1702 by Anton van Leeuwenhoek and for hundreds of years these microscopic creatures have been studied and analyzed. Richard B. Hoover contributed to this research by travelling the world, studying diatoms and collecting new species. In a June 1979 Edition of National Geographic, he published his exciting findings on these extraordinary organisms.

Below are some of the most exciting and intriguing findings regarding diatoms:

• While studying a diatom collection in Belgium, that had been dried on paper in 1834, Richard B. Hoover was shocked to find that after adding water to a slide, the diatoms were revived and began to swim around… after nearly 150 years!
• More than twenty-five thousand species of diatoms have been discovered, none of which have the same shell.
• Diatoms exist in large numbers in most bodies of water throughout the world. In fact, just one liter of seawater can contain as many as ten million diatoms!
• The greatest numbers of diatoms exist in cold oceans.
• Diatoms can thrive wherever there is light, water, carbon dioxide, and nutrients. In some cases diatoms can even live out of the water – in moist conditions, they are able to live in topsoil, or attached to moss, tree trunks and even brick walls.
• Diatoms are very resilient and can endure lengthy droughts.
• Diatoms vary greatly in size, with the largest measuring only one millimeter across.
• A species of diatom found on Cape Cod, known as Hantzschia virgata, bury themselves in the sand when the tide is in. Just after the tide goes out, the diatoms glide to the surface in order to sunbathe. Their timing is impeccable, as they know precisely when to bury themselves back in to the sand, retreating just moments before the tide returns. In fact, it was discovered that even after keeping these diatoms for weeks in a laboratory their timing remained constant. They continued to dig in and out of the sand with such amazing accuracy that their actions could be used to predict the tide!
• Diatoms are impressive shell builders. They transform dissolved silicon into a silica almost identical to the gemstone opal.
• Diatoms contribute enormous amounts of oxygen to our atmosphere.
• Huge numbers of diatoms die and sink to the bottom of river, lake and ocean beds. In some areas, sea floors can be covered in a layer as deep as 984 feet (300 meters)! Over many years these layers of dead diatoms fossilize and become rich deposits of diatomaceous earth, or diatomite.