Earth Treasures: Chert Rock
By Chisom Ibemere
Chert is a hard, sedimentary rock that is composed of silica specifically the mineral quartz. It has been in existence and used by humans for various purposes for thousands of years.
The word “chert” is gotten from the term “cherta” which means “hard.” Chert forms from the accumulation of silica-rich sediments and the replacement of other minerals by silica.
Chert is commonly found in sedimentary rocks, especially in limestone and dolomite formations. It occurs as nodules, beds, or layers within these rocks.
Chert deposits can be found all over the world, with high occurrences in the United States, England, France, Germany, Australia, and Brazil, among other countries.
Chert has been widely used in making weapons and tools due to its hardness by ancient civilizations.
It was used to make arrowheads, knives, scrapers, and various other cutting implements. It was utilized in the construction of structures, roads, walls, and other architectural aspects.
Chert’s ability to produce sparks when struck against steel led to its use in the ignition systems of early firearms (flintlocks). It was also used in prehistoric fire-making techniques, such as flint and steel.
Chert is basically composed of microcrystalline quartz and small quantities of other minerals, such as calcite, clay minerals, or iron oxides. It ranks around 7 on the Mohs hardness scale, making it quite hard and durable.
It comes in various colors of gray, white, brown, red, and black. It can also display patterns such as stripes, bands, or spots, depending on its impurities and formation processes.
Chert does not have a significant economic value on its own. Its value lies more in its historical and archaeological significance, as it provides insights into human development and cultural practices, particularly in prehistoric times.