This is Why a Fire Burns Everything But the Matches That Start It

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California is in its fire season again, and drier than usual, so many of us have spent days watching the devastation that a fire can cause. Few things survive it, even in bits and pieces. Often, though, the matches that began the fire are the most recognizable things left behind. Why is that?

Diatoms swim around the oceans and lakes, and have been doing so for a very long time. They come in an extraordinary variety of forms. They can look like slender ovals, or hairy sticks, or aerated flying saucers. Their forms are reinforced by shells of hydrated silicon dioxide. This is a mixture of silicon, oxygen, and water molecules that is very similar to glass or opal. The shells of these creatures produce layer after layer of rock in some places. Because the shells are fine, hard, and pointy, they have a variety of uses.


And crushed up diatoms are on the head of most matches. They help provide the friction that ignites the match, and they’re durable enough to survive multiple strikes. They are even durable enough to survive a fire. Fire investigators often find, in the smoldering remains of entire buildings, little heaps of powder from the matches that were used to ignite the building. Different brands of matches use diatoms from different quarries, so they can sometimes link up the powder and the brands. Diatoms are tough enough to not only start a fire—but survive it and “tattle” on the person who started it.

Top Image: CSIRO. Second Image: Hannes Grobe/AWI