A reaction that certain metals undergo when mixing with Oxygen, usually water vapor in the air, but any O2 containing molecule, resulting in a metal/oxygen compound and hydrogen gas. Something like
Oxidation as mentioned earlier is in a nutshell the “rusting" process for metals other then iron or steel.
Oxidation is the same process that a chemical battery uses to free up electrons produce electricity.
As Dann mentioned Mg will react with water in the air in addition to sweat. I would think that it would oxidize by just wearing and that other organic factors (skin oils, pH, electrolytes in sweat that would help complete the “battery circuit”) would aid the oxidation of the metal or even chelate Mg.
You are going to need to coat it in something that is acid free (several wax based polishes are acidic and lots of metal based paints are acidic self etching) as the metal is basic in nature.
Until you can find a suitable solution I would put it in an air tight jar with an open baggy of some desiccant like CaCl2 (often found as driveway melt, make sure to bake the CaCl2 for 30 min at 300 C to drive off excess water).
Ti and Al both oxide it is just that the oxidized metal from them doesn’t dissolve easily. Also, the oxidized metal acts as a coating of sorts preventing further oxidation via what I understand as the electron shell principal.
Electrons (or electricity) only travel on the surface of metals so electron exchange and oxidation can only occur at the surface and not in the middle of the metal block. So it won’t corrode from the inside unless there is a crack or bubble in the metal (because then your at the surface again).
I just polished it again and it claims it can form a protective layer to avoid oxidation.Hope it can last for a while. But anyway ,i want to keep it as a collection item and seldom wear it. Another thing is about the "Raw Magnesium" mentioned here should be "Raw Magnesium Alloy" actually, right? so i think it would not react exactly as the pure magnesium used in chemistry lesson .
Yeah it would be unlikely that they would use pure Mg, so it is most unlikely a Mg alloy. However, an alloy would act similar in some respects.
In addition, Mg is such a seldom used metal that it is hard to know what alloy and the particular characteristics of it, but there are some general characteristics that are common to all alloys.
It does look like that some alloys are less reactive than other like the alloy used for rims. I really don’t too much about the rims and the alloy used other than; they leaked air badly (very porous alloy), were a race item and had to be taken off the car and stored separately as they would corrode badly on the vehicle.
Sodium is a Group 1 metal along with Lithium, Potassium and Cesium etc. The react spontaneously with water to form an oxide and hydrogen gas.
Magnesium, being a group 2 metal, does not react spontaneous with water. It will react, only slowly and not in the spectaclular way of Group 1 metals. It will only behave like a group 1 metal if dropped into concentrated acid. Sorry Neil, but your memory is off.
When we moved the lab I was researching in, we though out a bunch of old or expired chemicals, including water sensitive “metal compounds”(NaH, LiAlH4) and of course Na and K.
I was in charge of disposal.
So some friends and I went to a lake and started lobbing stuff in. Some of it sputtered about and some of it did nothing. So near the end of our supplies a friend grabs a small bag of LiAlH4 and angrily tosses the whole thing in (about the size of half a deck of cards) and it goes off shooting red sparks everywhere.