Magnesium is an essential nutrient for plants and animals. Plants need chlorophyll to photosynthesize, and chlorophyll molecules contain magnesium ions. ATP (adenosine triphosphate), the energy molecule, binds to magnesium in order to get its work done. Hundreds of enzymes that are necessary to metabolism need magnesium to function. In the human body most of the magnesium is stored in the bones. Magnesium deficiency shows itself in a myriad of ways, reflecting its crucial role in so many processes.

For that alone we should know something of magnesium. The highest dietary sources are leafy greens, beans, nuts, seeds, and whole grains. Magnesium is in fact found in almost all the food we eat and so deficiencies are rare in well-fed places.

And then there’s mag wheels:

That was a big thing in the 70s—outfitting your car with “mag wheels.” They were originally made from magnesium but they are mostly aluminum now. Magnesium is lighter than aluminum but it corrodes more readily and is more flammable. The image above is from an F1 site. True “mag” wheels are expensive.

Magnesium alloys are ubiquitous. There is hardly a place where they can’t be found. The world produced one million tonnes of magnesium metal in 2022, mostly from magnesite and dolomite ores. Magnesium compounds are also extracted from seawater. One million tonnes does not seem like much when compared to the annual production of copper (~20 million tonnes), chromium (~40 million), and aluminum (~70 million) but it’s still a heaping pile of stuff.

In the lab you could get strips of magnesium to ignite and they produced an intensely bright white flame. The old flash bulbs of yesteryear had magnesium in them.