Magnesium-24, the alkaline earth metal with a mass about three times larger than Beryllium-8

Mg-24 is a member of the alkaline earth metals with an atomic nucleus that showed up much later than Be-9 (note I said it was Be-9 not Be-8 that showed up in the first 20 minutes after the Big Bang. See my beryllium post to understand and appreciate the importance of this surprising result).  In the assembly processes that continue to build our universe, billions of years after the Big Bang, stars larger than our sun began fusing He-4 nuclei to form C-12, which then went on to fuse with three more He-4 nuclei to assemble Mg-24. Also, with additional nucleosynthesis neutron bombardment, Earth’s naturally occurring magnesium ended up containing a low percentage of two additioal stable isotopes; Mg-25 and Mg-26.

According to, Mg is the 9th most abundant element that our self-assembling universe continues to throw together in its large-star, fusion factories. In its pure man-made form, Mg exists as a shiny, gray, metallic solid, similar in appearance to the other five elements in the group-2 alkaline-earth metals.

As for our own planet, Mg at 13% is the forth most abundant element after Fe, O, and Si. And in seawater Mg is #3 after Na and Cl. Although Mg doesn’t explode in water as do the alkali metals, the metallic form of Mg will react vigorously with water to form H2 gas and Mg(OH)2, a weakly ionizing, alkaline base. Metallic Mg will also burn vigorously and brightly in air as it reacts with oxygen to form MgO. So the free metallic form is man-made and doesn’t naturally exist in Nature. Instead it is mostly found ionically bound to other elements in the form of magnesium salts. The metallic form is readily isolated by electrolysis from these salts. Alloyed with aluminum, Mg’s low mass and binding properties make it ideal for adding strength and light weight to construction. After Fe and Al, Mg is our most important structural metal.

Powdered Mg’s ability to burn with bright, hard to extinguish flames made it an effective fire-bomb weapon in WWII.  This property also had it being used as a flash powder in old time photography. It’s still used in fireworks and marine flares. Mg actually burns better than Na, even though Na explodes in water whereas Mg reacts with water much less dramatically. Na2O production is slower than that of MgO. Since Na has only one valence electron, it takes two Na to one O when it comes to burning in air.

An especially interesting and surprising use for Mg was discovered by a farmer in Epsom, England in 1618.  His water, good for healing cuts, was later found to be loaded with magnesium sulfate heptahydrate.  That became known as a product called Epsom Salts.  And did you ever hear of Milk of magnesia, i.e., MgO suspended in water? It is another old, well-known and well used human health product. Also, magnesium supplements may be good for restless leg syndrome, neuropathy, etc.

China produces 80 % of the world’s Mg but the US used to be the main supplier. Even as recently as 1995 the US produced 45% of the world’s supply!

Mg has plenty of commercial uses for us humans in our everyday lives, but here’s the really important thing, we totally would not exist without it! 

First of all, Earth’s plant life would not exist. Mg acts as the coordinator of the porphyrin ring in cholophyl. It serves exactly the same role as Fe does in coordinating the porphyrin ring of hemaglobin! Also, Mg plays an essential role in over 300 enzymes, it acts in Mg-ATP energy functions in both plants and animals, and helps stabilize polyphosphates such as those in DNA and RNA. 

Although Mg is present in every cell type of every organism on Earth, Mg can sometimes be replaced by manganese. But Mn is not very effective at the job. So don’t use it as a substitute. Obviously, one’s life depends on Mg. Bottom line, make sure you get enough of it in your diet. Many people don’t. 

The next higher mass atom group-2 is Calcium, Ca-40.