A 15-year study led by the Carnegie Institution for Science in the United States illustrates the origins and diversity of all known minerals on Earth, a historical work that will help reconstruct the history of life on Earth, guide the search for new minerals and deposits, predict potential properties for future life and facilitate the search for habitable planets. Habitat and life outside Earth.
In research papers published in the American Mineralogist and sponsored in part by NASA, Carnegie scientists Robert Hazen and Shaunna Morrison detail a new approach to grouping related types of minerals or separating new ones based on when and how they originated.
Once the origins of minerals are taken into account, the number of “types of minerals” – a newly coined term – comes to more than 10,500, a number that is nearly 75% more than the 6,000 minerals recognized by the International Minerals Association (IMA) based Only on crystal structure and chemical structure.
“This work fundamentally changes our view of the planet’s mineral diversity,” says Dr. Hazen, a scientist in the Earth and Planetary Laboratory at the Carnegie Institution for Science.
“For example, more than 80% of the minerals on Earth are mediated by water, which is therefore fundamentally important to the mineral diversity on the planet,” he explains. By extension, this explains one of the main reasons why the Moon, Mercury, and even Mars, have far fewer mineral species than Earth. “
“The work also tells us something very profound about the role of biology,” he adds. A third of the minerals on Earth could not have formed without biology: shells, bones, and teeth, or microbes, for example, or the indirect vital role of biology, such as creating an oxygen-rich atmosphere that gave rise to 2,000 minerals that would not have formed otherwise.
According to the article, nature created 40% of the types of minerals on Earth in more than one way – for example, abiotically and with the help of cells – and in several cases used more than 15 different recipes to produce the same crystal structure and chemical composition.
Of the 5,659 types of minerals recognized by Hazen and colleagues, nine arose through 15 or more different physical, chemical and/or biological processes, from near-instant formation by lightning or meteor strikes to changes caused by interactions between water and rocks or transformations in High pressures and temperatures spanning hundreds of millions of years.
To reach their conclusions, Hazen and Morrison built a database of all known formation processes for all known minerals. Rely on large, freely accessible mineral databases (mindat.org and rruff.ima/info), backed by thousands of primary research articles on the geology of mineral sites around the world, identified 10,556 different mineral groups and formation patterns.
In previous studies spanning more than a century, thousands of mineralogists around the world have painstakingly documented nearly 6,000 different “mineral species” based on their unique combinations of chemical composition and crystal structure. Dr. Hazen and colleagues took a different approach, focusing on how and when each type of mineral appeared over the more than 4.5 billion years of Earth’s history. “No one has ever done this huge task before,” Hazen says.
The study concluded that water played a dominant role in the Earth’s mineral diversity, being involved in the formation of more than 80% of the mineral species.
Life played a direct or indirect role in the formation of almost half of all known mineral species, while a third of known minerals – more than 1900 species – were formed exclusively as a result of biological activities.
Moreover, the trace elements play a disproportionate role in the mineral diversity of the Earth. Only 41 elements – collectively making up less than 5 parts per million of the Earth’s crust – are essential components of about 2,400 (more than 42%) of Earth’s minerals, and much of Earth’s mineral diversity was created in the planet’s first 250 million years.
About 296 known minerals are believed to predate Earth itself, of which 97 are known only from meteorites (with the age of some individual mineral grains estimated to be 7 billion years, billions of years before Earth). Solar System).
According to the study, the oldest known minerals are small and durable crystals of zircon, which date back nearly 4.4 billion years. At the same time, more than 600 minerals have been derived from human activities, including more than 500 minerals resulting from mining, 234 of which resulted from fires in coal mines.
According to the research, 3,349 (59%) of the IMA approved mineral species are known to come from one process (paragenic mode), 1,372 (24%) from two processes, 458 (8%) from three processes and the remaining 480 (8 %) of four or more operations.
The articles explain other considerations about the grouping and classification of minerals, such as the era in which they were formed. It also appears that hundreds of different minerals may have formed on Earth before the giant impact that evaporated much of the planet’s crust and mantle and led to the formation of the Moon about 4.5 billion years ago. If so, those minerals have been erased, only to repair as the earth cooled and hardened.
In addition to the accidental metallurgical innovations in mine fires, mankind has produced countless thousands of metal-like compounds that are unqualified for IMA recognition: building materials, semiconductors, laser crystals, special alloys, gemstones, synthetics, plastic scraps and the like. However, they are all “prone to persist in the geological record for millions of years, providing a clear sedimentary horizon that characterizes the so-called ‘Anthropocene'”.
Meanwhile, there are 77 “vital minerals,” according to the paper, made up of a variety of metabolic processes, from corals, shells and nettles to minerals in bones, teeth and kidney stones.
Another 72 minerals come directly or indirectly from the guano and urine of birds and bats. This list includes the rare mineral spheniscidite, which forms when penguin urine (order Sphenisciformes, hence the mineral’s name) reacts with clay minerals under a rook colony on Elephant Island in the British Antarctic Territory. The authors note that ocean formation, extensive evolution of continental crust, and possibly even the initiation of an early form of subduction (the process that drives tectonic plates today) in the early Hadian period, between 4,000 and 4,500 million years ago, meant that many important processes for the formation of Minerals—and as many as 3,534 types of minerals—occurred in the first 250 million years of planet Earth.
The work also points the way for future researchers and explorers about the mineral-forming environments that occur on the Moon, Mars, and other worlds.