No, steel is not a mineral.
Since it does not exist naturally (without the interference of humans), it is not considered a mineral.
Why Is Steel A Mineral? (Or Not?)
What Makes Something A Mineral?
In this article, we are talking about the geological qualifications to consider something a mineral.
There are judicial, legal, and perhaps even social definitions for what constitutes “a mineral.” But these definitions go beyond the scope of this article.
Geologically speaking, a substance must meet five separate qualifications to be a mineral. If the substance fails to meet any one of the five, it is not a mineral.
The qualifications are:
One: The substance must be one that exists in nature. Humans can make it as well, but it needs to exist in nature on it’s own without humans making it or interfering.
Two: At normal temperatures on Earth, the substance must be a solid.
Three: The substances must be entirely inorganic. This doesn’t mean free of pesticides. This means that it is chemically an inorganic substance, which means usually that it does not contain any carbon to hydrogen bonds (C-H).
Four: The chemical composition of the substance needs to be the same all over. This means that a sample of one area must match a sample from another area.
Five: The substance must have an orderly structure.
What Is Steel?
Before taking steel through the five qualifications, let’s talk first about what steel is.
We have a feeling that once you understand more about steel, it’ll be pretty obvious how the qualifications apply to it.
Steel is not an element. Instead, steel is a mixture.
Steel is an alloy of iron plus carbon, manganese and small amounts of other materials. There isn’t just ‘one way’ to make steel. Different materials are added to the iron to make is stronger or more versatile.
The percentages of these metals and materials vary.
To make steel, the solid elements (like iron) are heated up until they become liquid. Once in liquid form, the materials are incorporated and mixed.
Then as the mixture cools, it becomes a solid again.
Does Steel Meet The Qualifications To Be Considered A Mineral?
No, steel does not meet the qualifications.
The most obvious reason is that steel does not exist in nature without the involvement of humans.
The ingredients of steel exist in nature: iron, carbon, manganese, and more.
But they don’t exist together in nature as steel exists.
Could iron be found liquid on this Earth? Yes, of course. Lava.
Could that melted iron contain other trace elements? Yes, of course. Happens all the time.
Would the combination of those materials result in steel? Really unlikely.
Steel isn’t just about mixing iron up with other elements. It has a pretty darn precise mixture to produce the end product that is steel.
Further, you also have to remember that steel is mixed thoroughly and with the purpose of making sure that all of the ingredients in it are spread out consistently through the material.
The last thing the producer would want is to have any areas of the resulting metal crack or fail because there wasn’t enough of the other elements mixed in.
Commercial steel is probably as close as you can get to being chemically consistent throughout.
But melted iron out in a volcano somewhere would not have consistent amounts of other metals or elements melted/mixed into it.
We wouldn’t/couldn’t call it steel.
To be fair, steel does meet some of the mineral qualifications.
It is a solid at normal for Earth temperatures.
It is chemically consistent throughout (though steel varies in grade).
And finally, steel is completely inorganic.
But it is still not a mineral.
But What About Stainless Steel? Is Stainless Steel A Mineral?
No, geologically speaking, stainless steel is not a mineral, for the same reasons that regular steel is not a mineral.
Stainless steel is an iron-based alloy with a lot of chromium in it to prevent the iron from rusting.
Like steel, it is a mixture, not a compound or an element.
Stainless steel is made pretty much like steel is made: in a factory by humans. Melting the iron ore and then mixing in other ingredients, and then letting it cool.
Stainless steel does not exist in nature on it’s own, without the involvement of humans.
Since stainless steel is not natural (though it is a solid and is inorganic), it is not a mineral.
You might also like: Is Titanium Stronger Than Steel?