The world’s most abundant mineral has remained nameless because scientists couldn’t find a natural sample of it to characterize. After 50 years of dogged searching, scientists have discovered a specimen inside a meteorite that slammed into Earth in 1978.
The mineral, which has been characterized in the journal science, will now be known as bridgmanite in honor of Percy Bridgman, an American physicist and Nobel laureate.
The Earth’s lower mantle comprises more than 50% of the planet by volume and extends from 670 to 2,900 kilometers in depth. Pressures in this region begin at 237,000 times the atmospheric pressure and even reach 1.3 million times atmospheric pressure.
Although scientists don’t know a great deal about the lower mantle, it’s thought to be largely composed of a super dense version of magnesium iron silicate. The International Mineralogical Association requires that a mineral can only be named after it has been analyzed in its natural state. The reason it has been so difficult to find is that, while it makes up some 38% of Earth’s entire volume, it is extremely rare at the Earth’s surface, and it’s only typically stable at pressures found more than 670 kilometers below the surface.
The mineral’s new name, bridgmanite, is in honor of Percy Bridgman, a scientist who won the 1946 Nobel Prize in Physics. Bridgman pioneered techniques that allowed scientists to synthesize and analyze minerals at pressures akin to those experienced deep within our planet.