Chapter 3: The First Minerals

Minerals Appear as Earth Cools

As the young Earth continued to lose heat, the molten surface began to stabilise. Temperatures were still extremely high, but they were finally low enough for the first minerals to appear. These earliest minerals formed directly from cooling magma and were simple in structure compared to the wide variety we know today.

Inside the slowly solidifying crust, different elements combined in specific ways depending on temperature, pressure and chemical conditions. Minerals such as olivine, pyroxene and feldspar formed first because they crystallise at the highest temperatures. These minerals created the base of Earth’s earliest rocks.

Deeper inside the planet, crystals also began to grow within pockets of magma that cooled slowly. This allowed larger and more well-formed crystals to develop. Meanwhile, volcanic eruptions at the surface carried molten material outward, where it cooled quickly and formed fine-grained minerals.

Water now played an important role. As the planet cooled further, water interacted with hot rock and helped create new minerals through chemical reactions. This included clays and early forms of quartz that began filling cracks and empty spaces within the crust.

These early minerals formed the foundation for all later geological processes. They became the building blocks of Earth’s first stable rocks, and from these rocks, the long story of mountains, oceans and continents began.

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