Yes, Chert can scratch glass because it is much harder and stronger than regular glass.
People often do the glass scratch test with a mineral or stone to see if it is real and give insight into what the stone is.
In this article, we will do an overview of glass and Chert, why Chert scratches glass, how to do an official test, and how to identify Chert in nature.
Can Chert Scratch Glass? (INFO AND EXPLANATION)
This sedentary rock was crucial in developing tools and advancing civilization during prehistoric hunter-gatherer times.
Even as things advanced, Chert still became integral in developing infrastructure, designing cityscapes, and constructing new materials.
In today’s world, it is a celebrated source of silica, and when mining, a strong indicator of large deposits of iron, manganese, petroleum, and uranium.
Chart Physical Properties
This is a fine-grained sedimentary rock made of microcrystalline or cryptocrystalline quartz.
It’s usually found near limestone, chalk, gem, and other similar minerals.
Large deposits are in Arkansas, Oklahoma, Texas, South Carolina around the rivers and the ocean.
It can be found as a thick three-foot layer in the ground, angular broken chunks beside a river, or even embedded within other stones such as limestone.
This stone can be found in all colors, depending on the ground impurities in the area.
There are many types of Chert, of which the most common are Flint, Common Chert, Agate, Jasper, Onyx, and Opal.
Chert Metaphysical Properties
Chert is said to have a calming and lightening effect for its wearers and helps with memory, peaceful sleep, and preparing for healing work.
Some also believe this stone can help redirect energy within a person’s body by releasing unwanted and unneeded burdens and blocks.
The first known records of glass were around 3,600 years ago in ancient Mesopotamia and Egypt.
It was purely used for decoration purposes for thousands of years until the Roman Empire.
They were one of the first ancient societies to begin using glass in architecture as windows.
Glass production went through a major shift in 1674 enabling people to make more types of glass than ever before.
The different types allowed for all new industrial and scientific purposes for glass.
Glass Physical Properties
Glass is a hard substance, typically transparent or translucent that, at a certain temperature, becomes a non-crystalline, amorphous solid.
There is both manmade and naturally occurring glass.
The most common type is silicate glass, which is mainly silica or silicon dioxide.
This is what you commonly find in windows and drinking glasses.
Impurities and compounds are added as needed to change the color and customize the glass for its specific purpose.
Why can Chert scratch Glass?
The Mohs Hardness Scale is a way of rating minerals by their ability to scratch other minerals and then arranging them on a scale of 1 to 10.
Scientists determine the order by taking two minerals and seeing which one damages the other.
The mineral that wasn’t damaged, will receive a higher number on the Mohs Hardness scale than the other.
Glass is a good point of reference for Moh’s hardness scale because it is in the middle of the scale and because most people have scratched it before intentionally or unintentionally.
Chert has a rating of seven on the Mohs hardness scale, while glass has a rating of 5.5 on the scale.
These ratings indicate that Chert can definitely scratch glass.
The reason for this is because Chert is made of microcrystalline or cryptocrystalline quartz that can form itself into nodules, concretionary masses, or layered deposits.
The crystalline structure and molecular arrangements in Chert have a lot more strength than that of glass.
How to do an official glass test:
- Take a glass tile or a stable piece of glass
- Select a rough or pointed edge of the stone
- Press the pointed edge of the stone against the surface of the glass tile and try to draw a straight line
- Remove and check for any scratch on the glass *If there is a “scratch,” make sure it is one and not a removable mark*
- If the stone has multiple shades, perform the test on different areas of the glass surface and areas of the stone
Chert can be a unique landscaping rock to add to your property or it can be bought in large beautiful chunks at a rock and mineral show.
Thicker pieces from deeper in the earth are often used in buildings or bridges with structural concrete and steel.
The most popular type of Chert stone is Flint.
Since it is found so commonly in nature, we will teach you how to identify Flint.
Flint will likely appear black or dark gray and sometimes form bands along the surface.
Also, Flint has a natural, glassy luster, almost like the graphite from pencil lead.
Depending on the area, some Flint will be buried in chalk, so don’t be afraid to thoroughly wipe it off before testing it.
Most Flint rocks will appear almost like broken glass shards, but occasionally as smooth, rounded shapes too.
Always remember to do a scratch test with glass class as well as a strike test with Carbon Steel to see if you can get a spark.
There are also forms of Chert that are fashioned into jewelry.
These Green, Chert Jasper, Brown, and Blue Chert stones are heavily concentrated within the Northern United States Area.
Because Chert is not a particularly expensive stone, it’s not likely for you to find any fake Chert jewelry.
Whether you are testing to see if a stone is Flint, or a more expensive classification of Chert, doing a glass scratch test is essential for you to gain clarity about the nature of almost any stone or mineral.
With the information above, you now know why real Chert should scratch glass and how to identify natural Flint, the most popular form of Chert, in nature.
All this will enhance your knowledge about Chert, help you know why the glass test works, and how to use it as a tool to grow your gemstone collection.