No. Feldspar is not magnetic. This article will explain the science behind the non-magnetic nature of this intriguing substance called feldspar.
Is Feldspar Magnetic? (Explained)
Feldspar is the most common rock-forming group of minerals found beneath the earth’s surface.
The term feldspar does not refer to a single mineral.
It encompasses a wide variety of compounds combined to form this essential component of the earth’s crust.
In fact, feldspars are so essential that rocks are often classified based on the content of feldspar.
These minerals are crucial components in igneous, sedimentary, and metamorphic rocks.
Chemically, feldspars are a group of aluminum tectosilicate minerals that may contain sodium, calcium, potassium, or barium.
Tectosilicates- also known as framework silicates-are silicates in which all corners of the silicate tetrahedra are bonded to corners of other silicate tetrahedra, forming a complete framework of silicate tetrahedra in all directions.
It is tricky to classify feldspars solely as metals due to an assorted blend of minerals in them.
Sodium, aluminum, and calcium are weak metals, while silicon is usually described as being metalloid.
Feldspars contain the general chemical composition, X(Al, Si)4O8, where X is commonly potassium, sodium, or calcium, but on rare occasions, barium, rubidium, or strontium.
The ternary system is used to express the mineralogic composition of feldspars;
- Orthoclase (KAlSi3O8)
- Albite (NaAlSi3O8)
- Anorthite (CaAl2Si2O8)
These three silicate compounds can be combined to give the two main types of feldspars;
- Alkali feldspars: a mixture of Albite and Orthoclase
- Plagioclase feldspars: a mixture of Albite and Anorthite
The physical properties of feldspars are unexpectedly similar despite having different chemical compositions.
The commonly observed physical properties include;
- Two directions of perfect cleavage that intersect at or close to ninety degrees
- Mohs hardness of approximately 6 to 6.5
- Specific gravity between 2.5 and 2.8
- Vitreous luster that is often pearly on cleavage faces
- Usually white, pink, gray, or brown
In addition, feldspars do not have a fixed melting point; they melt gradually over a range of temperatures.
They possess reasonable chemical inertness, stable pH, and good dispersibility.
What does magnetic mean?
To understand what the concept of a substance being magnetic means, we need to refresh our memory on what these commonly used terms actually mean.
A magnet is a metal or rock that has the ability to pull particular types of metals onto itself.
This essentially means that not all metals are attracted by magnets.
Magnets achieve this feat by producing an invisible field called the magnetic field.
This field pulls on ferromagnetic compounds such as iron, nickel, and cobalt and attracts or repels other magnets.
The lodestone is a good example of a naturally occurring magnet.
A magnet can be made by rubbing a piece of an existing magnet onto a piece of appropriate metal.
Magnetism is a phenomenon that happens when an object is exposed to an applied magnetic field.
All objects are made up of tiny particles called atoms.
These atoms are further made up of electrons, neutrons, and protons.
Electrons spin around the nucleus of an atom.
As these electrons spin, they create tiny magnetic forces.
Magnetism occurs when electrons within an object are made to behave in a certain way.
When many of these electrons within an object spin in the same direction, these tiny magnetic forces combine to create one big magnetic field.
There are several forms of magnetism and most materials possess at least one form.
They include ferromagnetism, ferrimagnetism, paramagnetism and diamagnetism.
However, ferromagnetic and ferromagnetic objects are truly thought of as “magnetic”.
This is because their magnetic forces are strong enough to physically attract them to a magnet.
Paramagnetic and diamagnetic objects are so weakly magnetic that they are usually thought of as “non-magnetic”.
Why are feldspars non-magnetic?
Feldspars contain aluminum tectosilicates with sodium, potassium, or calcium.
All these compounds belong to the group of paramagnetic materials.
The attraction of these paramagnetic materials to magnets is hundreds of thousands of times weaker than that of ferromagnetic materials.
Thus, no physical attraction is generated.
Feldspars generally do not contain ferromagnetic and ferromagnetic compounds such as iron, cobalt, and magnetite.
This makes them unable to be attracted to even powerful magnets.
In fact, this physical property has been employed by geologists as a means to purify feldspars.
Strong magnets are used to separate magnetic impurities such as iron and nickel from rocks containing feldspars.
The feldspar molecules are not affected by these strong magnetic fields.
Rock magnetism can help amateur and even experienced geologists have an insight into the formation of rocks and land patterns.
On the one hand, feldspars contain non-magnetic minerals and, as such, are not under the influence of the earth’s magnetic field.
On the other hand, magnetic rocks tend to align themselves with the orientation of the earth’s magnetic field.
The concept of paleomagnetism-the permanent magnetism in rocks, resulting from the orientation of the Earth’s magnetic field at the time of rock formation- is now used as a source of information for continental drift and polar wandering.
Rocks rich in feldspars do not exhibit this trait.
Feldspars are rock-forming materials composed of aluminum tectosilicate minerals that make up most of the earth’s crust, where they occur as alkali feldspar or plagioclase feldspar.
They are non-magnetic in nature owing to the lack of ferromagnetic and ferromagnetic materials as part of their chemical composition.
Their non-magnetism makes it possible for rocks rich in feldspars to be differentiated from magnetic rocks as the latter tend to align with the earth’s magnetic field.
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