Diatoms

By Kathy Kranking

Is this an ornament you might see on a holiday tree? Nope—it’s something completely different! Welcome to the secret world of diatoms!

So, what exactly are diatoms (DYE-uh-tomz)? These supercool living things are types of plant-like algae (AL-jee). Most of them are smaller than the width of a human hair—so tiny that they can be seen only with a microscope! The picture above is made up of mega-magnified diatoms that have been arranged into a snowflake pattern. The photos here also show different kinds of magnified diatoms. There may be more than two million species of diatoms, and each kind has its own unique shape.

Diatom microscope — Too tiny to see, diatoms are placed on a glass slide so they can be viewed through a microscope.

Diatoms live anywhere there’s water—including oceans, lakes, rivers, streams, ponds—even moist soil. Most living diatoms are a golden-brown color. The other photos in this story had color added by computer.

GLASS HOUSES

One of the most amazing things about diatoms is that they live inside their own beautiful shells. A diatom makes its shell by taking silica (SIL-ih-kuh) from water. Silica is what glass is made of. It’s as if the diatom lived in a glass house! The shell of a diatom usually has two halves, with the top fitting over the bottom the way a lid fits on a shoebox.

MINI BUT MIGHTY

Even though diatoms are so small, they’re some of the most important things on Earth. That’s true for two reasons. First, diatoms are food for many tiny animals. Those tiny animals are food for bigger animals, and those animals are food for even bigger animals. So diatoms are an important part of the food chain. Without them, many water animals wouldn’t be able to survive.

The second reason diatoms are so mighty is that they take in carbon dioxide and give off oxygen. Scientists think that 20 to 40 percent of the oxygen we all breathe is made by the trillions of diatoms around the world. So, take a deep breath and thank a diatom!

MICROSCOPIC ART

Just as the pretty picture at the beginning of this story was, all the beautiful creations on this page are made from diatoms! Diatom art became very popular about 150 years ago, when people became interested in looking at things through microscopes.

To make diatom art, the diatoms’ insides are washed out with acid. That leaves just the beautiful glass shells.

Arranging these shells into kaleidoscope-like patterns isn’t easy. It’s all done while looking through a microscope. The diatoms are placed on a glass slide that’s covered with a slow-drying gluey liquid. The diatoms are so tiny that the person arranging them uses a human hair or a needle to move them around. After hours, or even days, of painstaking arranging, a mini-masterpiece is complete!