No, diamond is not usually a pure substance.
That being said, under the right circumstances, diamond could be a pure substance.
In the article that follows, we’ll explain what a pure substance is, why it is that diamonds usually don’t qualify, and what would have to happen for diamonds to be considered a pure substance.
When Is Diamond A Pure Substance?
What Is A Pure Substance?
First, let’s talk about what a pure substance is.
A pure substance is scientifically a substance made up of only one kind of building block.
That building block could be an element.
Or that building block could be a compound.
The key is that the substance is question be made up of only element or compound, with nothing else added.
What Is A Diamond?
A diamond is a solid form of the element carbon.
The thing that makes it special is that arrangement of its atoms, in its rigid crystal structure.
With its structure, diamond is the hardest and most conductive of any natural material.
If Diamond Is Made Of The Element Carbon, Why Isn’t It A Pure Substance?
In theory, diamonds seem like they would be the ideal pure substance.
After all, a pure substance is made up of only one element or compound.
And in a controlled environment, diamonds can be made completely of carbon.
But real life is rarely so simple, and substances on Earth are rarely (if ever) created naturally in such a controlled environment.
The reason why diamonds do not qualify as a pure substance is that they are rarely pure.
In fact, most diamonds (even the ones that look the clearest and most beautiful to your eyes) contain impurities.
Diamonds often contain other chemicals or minerals, such as: boron, nitrogen, oxygen, silicon, and more.
These impurities cause diamonds to vary in color (yellow, red, brown, pink, blue, green, etc) and clarity.
And just because you can’t see the impurity with your eyes (or a jeweler’s tool), doesn’t mean it isn’t in there down at the molecular level.
Because diamonds are not made up of one element, but instead contain impurities that are not bonded to the carbon, diamonds are not considered a pure substance.
Is Diamond A Mixture?
Yes, we consider diamond to be a mixture.
A mixture is a substance made up of more than one material, where the materials in the substance are not bonded to each other.
In the case of diamonds, most of the material is carbon. Within the carbon, you’ll find the impurities in trace amounts.
These impurities (various elements or other compounds) are not chemically bonded to the carbon.
Since the impurities are not bonded to the carbon, the diamond is considered to be a mixture.
That being said, if the diamond material had absolutely no impurities or other elements, molecules, or compounds within its makeup, we wouldn’t call it a mixture. We’d call it a pure substance.
Is Diamond A Homogeneous or Heterogeneous Mixture?
We’d call diamond a heterogeneous mixture.
In general, a homogeneous mixture is one that is consistent throughout.
A heterogeneous mixture is a mixture that is not consistent throughout.
When a diamond is formed, the impurities that end up solidified into its rigid structure are usually not evenly spread out. There’s usually a little bit over here, and a little but over there.
One area might contain nitrogen, while another area might contain boron.
It is probably possible to come across a sample of a diamond that is chemically and physically consistent throughout the material, but we wouldn’t expect it to be that way.
This is why we call diamond a heterogeneous mixture.
Is Diamond A Compound?
No, diamond is not considered a compound.
A compound is formed when at least two different kinds of materials (elements or other compounds) form bonds to each other.
In the case of diamonds, the base material carbon is actually bonded to other carbon atoms.
The thing is, to be considered a compound, the material must be made up of two different kinds of substances.
Thus, to be a compound when composed of elements, there must be at least two, like we see in salt (which is sodium and chlorine).
Diamond (carbon bonded to carbon) is considered to be made up of molecules, rather than of a compound.
Other single element molecules (that are not compounds) include oxygen gas (oxygen bonded to oxygen), hydrogen gas (hydrogen to hydrogen) and nitrogen gas (nitrogen to nitrogen).
Is Diamond An Element?
No, we don’t consider diamond an element.
An element is any material that cannot be broken down or apart into simpler substances.
In the case of diamond, the material can be broken down into simpler substances, such as carbon, and the other various impurities in the material.
And even with the case of the carbon molecule, these bonds can be broken apart to create a more simple substance (single carbon atoms).
Diamond is made of an element, but it itself is not an element.