The question of what is the world's most abundant mineral seems straightforward, but the answer is surprisingly nuanced. It depends entirely on what part of the Earth you are talking about. While common minerals like quartz and feldspar are plentiful on the surface and in the crust, the majority of the planet's volume is comprised of a single, high-pressure mineral that was only officially named a decade ago.
The True Champion: Bridgmanite
Bridgmanite is the most abundant mineral on Earth by volume. Located in the lower mantle under intense pressure and heat, this magnesium-iron silicate ((Mg,Fe)SiO3) makes up approximately 38% of the planet's total volume.
Discovery of a Hidden Mineral
Due to its instability at lower pressures, bridgmanite cannot be retrieved from Earth's deep interior for study. Scientists first identified natural bridgmanite in a meteorite that impacted Australia in 1879, where the shock of the collision created conditions similar to the lower mantle, preserving the mineral. It was formally named in 2014 in honor of Percy Bridgman.
Properties and Significance
- Formula: (Mg,Fe)SiO3.
- Structure: Perovskite structure.
- Location: Lower mantle (410 to 1,796 miles deep).
- Function: Dominant phase in Earth's lower mantle.
Abundance in the Earth's Crust
While bridgmanite is dominant deep within the planet, the most abundant mineral group in the Earth's crust is feldspar.
The Feldspar Group
Feldspar is a group of silicate minerals making up over 50% of the Earth's crust. Composed of aluminum, silicon, oxygen, and elements like potassium, sodium, and calcium, feldspars are found in most rock types and are used in industries like ceramics and glass manufacturing.
The Most Common Surface Mineral
Quartz (SiO2) is the most abundant mineral on the continental surface. Its durability and resistance to weathering make it a major component of beaches, riverbeds, and sedimentary rocks like sandstone. It is the second most abundant mineral overall in the Earth's crust.
A Comparison of Earth's Most Abundant Minerals
| Feature | Bridgmanite | Feldspar Group | Quartz |
|---|---|---|---|
| Abundance | Most abundant overall (38% by volume) | Most abundant in the crust (approx. 50%) | Most abundant on continental surface |
| Location | Lower Mantle (660–2900 km deep) | Earth's crust (continental and oceanic) | Primarily continental surface |
| Chemical Formula | (Mg,Fe)SiO3 | XZ4O8 (X=K,Na,Ca; Z=Si,Al) | SiO2 |
| Stability at Surface | Unstable; changes structure | Less stable than quartz; weathers to clay | Highly stable; resistant to weathering |
| Formation | High-pressure, high-temperature conditions | Crystallizes from cooling magma | Excess silica left after other minerals crystallize |
The Most Common Mineral Groups
Other abundant mineral groups include silicates like pyroxenes (about 11% of the crust), amphiboles (about 5%), and micas (about 5%). Olivine is a key mineral in the upper mantle.
Conclusion: Perspective is Everything
Ultimately, what is the world's most abundant mineral depends on your perspective. By total planetary volume, the clear answer is bridgmanite, an elusive deep-earth mineral that comprises over one-third of the planet. However, in the Earth's accessible crust, the feldspar group takes the top spot, while quartz dominates the continental surface due to its exceptional stability. Each of these minerals, found at different layers of our planet, tells a unique story about the dynamic forces that shape Earth. For more on mineral classification, refer to Mindat.org.
