As many would agree, the earth is a fascinating treasure pit with a lot of natural wonders that even experts cannot explain. One such wonder is minerals. Minerals in this context refer to naturally occurring solid chemical compounds that have defined internal chemical compositions, crystal forms, and clearly defined physical properties that are recognizable.
A mineral must be a naturally occurring substance created by a natural geological process in order to qualify as one. Over the years, experts have been able to identify and name thousands of minerals, expertly studying them and deducing the timeline that marked their formation. Many of these minerals are older than we think; some even predate the existence of humans. What do you think is the oldest mineral found on earth? This article answers. Keep reading to find out.
What Is the Oldest Mineral on Earth?
The oldest mineral ever found on earth is zircon. The oldest samples of this mineral date back over 4.4 billion years ago, making it almost as old as the earth itself. It is common in most sand and sedimentary deposits, as well as metamorphic rocks and crystallized magma.
The first step in finding and naming minerals is finding locations with mineral deposits. Depending on the situation, these locations are found through satellite images or geochemical surveys.
Where Was Zircon First Found?
According to experts, the oldest samples of zircon were found in Jack Hills of Western Australia, and they were almost 4.4 billion years old. This proves that the mineral first formed in the earth’s crust while the earth was in its infancy, only roughly 200 million years old. However, considering that the age of the other samples discovered nearby ranged up to three billion years, these minerals represent the closest thing scientists have to a consistent chemical record of the early Earth.
Each zircon includes uranium, which allows for a highly accurate age determination. Scientists can determine the age of uranium by measuring its famed radioactivity and quantifying its rate of decay. This same method was used to determine the age of the zircon pieces found. The team of scientists used a laser blast and a mass spectrometer to test more than 3,500 zircons for their chemical makeup. These analyses provided information about the chemical and age of each zircon. Due to the damage these minerals had sustained over the billions of years since they were formed, only 200 of the thousands of samples analyzed were suitable for research.
How Was Zircon Formed?
According to experts, this mineral is believed to have formed from magma or metamorphic rocks. The mineral zircon is created when zirconium, silicon, and oxygen condense in magma or metamorphic rock. Because of its chemical composition, zircon can survive geological processes like erosion. Although this mineral is not physically affected by these geologic events, it acts like a time capsule and records them. In other words, it is easy for experts to figure out the chronology and details of major geologic events by studying zircon samples. The amount of information experts have on the earth in its early days would have been limited without the help of zircon.
Zircon contains uranium, which changes the mineral’s color and chemical composition over time to indicate changes in the environment and also give clues on the earth’s formation. While this is happening, the zircon’s core is unaltered and still retains the chemical properties of the rock in which it first crystallized. Because of this, it is easy for scientists to laser open a piece of zircon and, with accurate precision, figure out the timelines of some of the most important happenings in the world. Zircon also helped scientists understand the formation of some continents, life on earth before humans, and facts about other planets.
What Does Zircon Look Like?
Although commonly reddish-brown, zircon comes in different colors; orange, yellow, red, green, and sometimes even colorless. It is also usually translucent, but in some cases, it appears transparent. Despite already coming in multiple colors, this mineral still changes color when heated. Blue zircons are the most common shade, and the price will increase as the shade of blue becomes more intense. Traces of specific impurities, some of which are radioactive, are what give it its variety of colors.
What is Zircon Used For?
Zircon has multiple uses for different industries, and one of the sectors that use the mineral the most is ceramics. The mineral is finely ground to make glazes and enamels. Additionally, it is utilized in the manufacture of tiles and ceramic pigments and as an opacifier to enhance the whiteness of these pigments.
Zircon is very frequently used in jewelry due to its range of colors and toughness. The mineral has been used as a gemstone for over 2,000 years. When zircon is carved into facets, it may dazzle brilliantly and is a less expensive alternative to diamonds. However, its toughness makes it more difficult to beat into finer jewelry like rings. In the steel industry, zircon is used to line furnaces because of its high melting point, usefulness as an abrasive, and hardness. Other applications for zircon products include spacecraft, electronics, and engines.
Despite being so old and helpful, zircon is not a rare mineral. It can be found in the crust of the earth and is also a common mineral found in igneous, metamorphic, and sedimentary rocks. However, larger zircon pieces are harder to come by, unlike the smaller ones. Zircon can be found in multiple parts of the world. Still, some of the most common places it is found include Australia, Brazil, Korea, Madagascar, and Niger.
The photo featured at the top of this post is © iStock.com/danyskar
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- , Available here: https://geologyscience.com/minerals/zircon/
- , Available here: https://www.americangemsociety.org/birthstones/december-birthstones/history-of-zircon/
- , Available here: https://www.vedantu.com/geography/zircon