Yes, kimberlite is strongly magnetic.
The remainder of this article will give you an in depth look at kimberlite, what it looks like, where it came from and what it’s used for.
Is Kimberlite Magnetic? (EXPLAINED)
In the world of science, there are millions of explanations as to the way an object reacts.
One such amazing yet puzzling occurrence is called magnetism.
Kimberlite is a peculiar igneous rock that exhibits very strong magnetism.
Due to the trace mineral, Magnetite, that is found inside this heavy, diverse looking rock, it has very distinctive magnetic and electromagnetic signatures.
What Is Kimberlite?
The material referred to as kimberlite, also called blue ground, is a dark-colored, often fragmented, intrusive rock that contains diamonds in its rock matrix.
Since kimberlite was first discovered in South Africa in 1869, it has been the most important source of diamonds in the world.
They contain a variety of minerals with chemical make-up that indicate they were formed under high pressure and temperature within the mantle.
Its most abundant minerals include olivine, garnet phenocrysts, serpentine, calcite, and magnetite.
Kimberlites are magmatic rocks that form deep in Earth’s interior and are brought to the surface by volcanic eruptions.
These volcanic explosions produce vertical columns of kimberlite rock that rise from deep magmatic reservoirs.
Their classical carrot shaped pipelike structures are important for delivering diamonds to the crust of earth’s surface.
Initially, the origin of diamonds was still unknown and the precious gems were thought to have been found in alluvial deposits.
This is because of a phenomenon that occurred in South Africa whereby the tops of the two first known kimberlite pipes had been weathered down and the diamonds had been washed into the Vaal and Orange rivers where the diamonds were first found.
About 6,400 kimberlite pipes have been discovered in the world.
Though Kimberlite can most often be found in Southwest Africa, this worldly rock is also indigenous to New York, Australia, Tanzania and many other parts of the world.
Deposits of kimberlite have also been found in the Prince Charles Mountains on the eastern side of Antarctica.
Scientists agree that mining will not take place on that continent.
What Does Magnetic Mean?
The term “magnetic” informally refers to any rock that shows visible attraction to a magnet.
This is because magnetism is what designates the forces that attract certain materials to one another or rejects them.
Generally speaking, magnetism is one aspect of the combined electromagnetic force.
Within the rock and gemstone world, magnetic susceptibility is the scientific term for the degree to which a gem is attracted to or repelled by a magnetic field.
Magnetism arises from the spin and orbital motion of electrons or electric charges.
Every substance is made up of tiny units called atoms.
Each atom has electrons, which are particles that carry electric charge.
Spinning like tops, the electrons circle the nucleus, or core, of an atom.
Their movement generates an electric current and causes each electron to act as a microscopic magnet.
In most matter, equal numbers of electrons spin in opposite directions, which cancels out their magnetism.
Although some rocks have electrons that are not paired with other electrons, the unpaired electrons are then free to align themselves with a magnetic field.
The result is magnetic attraction.
The rocks that don’t show magnetic attraction don’t have many unpaired electrons and are considered inert.
Why Is Kimberlite Magnetic?
People are generally surprised to learn that rocks, as a whole, can be magnetic.
This is because most rocks show no direct response to common magnets that we keep around the house such as a refrigerator magnet because these magnets are much too weak.
For the rocks that are magnetic, their degree of attraction can be noted from weak, moderate, or strong.
These rocks can range in magnetic strength from being capable of lifting steel rods to barely turning the needle on a compass.
The magnetism that we most often encounter in rocks and minerals is a certain kind of magnetism called Paramagnetic.
This type of magnetism is due to the presence of dissolved metals within the genetic make-up of the rocks.
Paramagnetism’s attraction can a million times weaker than Ferromagnetism, which is the kind of magnetism associated with iron, such as a paper clip.
Once a specimen is established as magnetic, identification of the specimen becomes a rather routine exercise.
There are a few methods to help find out if a rock is magnetic or inert, such as the floatation method, an N52 magnet and a UV flashlight.
Using a powerful neodymium magnet in combination with a near-frictionless testing method provides a means to detect even very slight magnetism.
Rocks can be separated from one type of rock to another, and sometimes identified, simply by observing which response a rock shows when the magnetic field of an N52 grade neodymium magnet is applied.
In certain materials such as magnetite, iron, nickel, or iron oxide, magnetism is naturally present, and it works without any exterior help.
One can find these materials occurring naturally by using of a magnetometer and the magnetic method.
The magnetic method is the geophysical method most widely used in searching for kimberlites.
On kimberlites’ turbulent journey upwards, magmas assimilate other types of minerals such as magnetite.
The unweathered portion of a kimberlite pipe generally contains a minimum of few percent magnetite as an accessory mineral.
This produces a clearly detectable magnetic anomaly because magnetite (hence the name) is the most magnetic mineral in the world.