(ORDO NEWS) — The unique work showed that water was involved in the formation of most of the earth’s minerals, thousands of them appeared thanks to living organisms, hundreds – from animal excretions, and the planet could become suitable for life in the first 250 million years.
American scientists have compiled a catalog summarizing the formation mechanisms of all known minerals of the Earth. Over 15 years of painstaking work, they summarized the results of thousands of previous studies, collecting information on 5659 minerals.
The unique catalog made it possible to divide them into 57 groups according to their origins and showed that most of them were formed in the presence of water. Judging by these data, water – and possibly life – could appear on Earth much earlier than it is believed.
The unique catalog will still bring new discoveries, but for now, a couple of articles ( 1 , 2 ) published in the American Mineralogist magazine talk about it .
Minerals are almost always considered and classified based on their composition and crystal structure. However, the work done by Robert Hazen and Shaunna Morrison of the Carnegie Institution relies on the processes that lead to their formation.
Scientists have shown that about 40 percent of minerals can appear in more than one way (for example, abiogenic and biogenic), and nine in more than 15 different ways.
The record holder here can be called pyrite (iron disulfide), which is formed in 26 different ways, from different combinations of starting materials, under completely different conditions and in different environments, from slow sedimentary deposits to meteorite impacts.
In total, geologists have identified 10,556 minerals and their formation mechanisms. The vast majority – more than 80 percent – require the presence of water.
About half are formed with the help of living organisms, and a third (1900 pieces) exclusively by such biogenic methods. 77 “bio-minerals” can be generated from the transformation of various living structures such as corals, shells and bones.
And another 72 are formed with the participation of guano and other animal secretions. Finally, more than 600 minerals have come from human activities, including 234 from coal combustion.
Rare earth elements play a special role in the mineral diversity of the Earth: although their content in the earth’s crust does not exceed five parts, they are part of approximately 2,400 minerals. Entire groups of minerals are associated with significant events in the geological history of the Earth.
Some of them appeared during the “oxygen revolution”, when free oxygen began to accumulate on the planet. A group of 350 minerals formed about 4.45 billion years ago when vast bodies of water appeared on the surface.
In addition, scientists conclude that a large part (more than 3500) of the entire variety of minerals appeared already in the first 250 million years of the Earth’s existence. 296 of them are even older than our planet, and 97 may come here with meteorites that are older than the solar system itself.
This shows that the geochemical conditions suitable for the development of early life formed on Earth shortly after its birth. “The work is fundamentally changing the way we look at the planet’s minerals,” adds Robert Hazen.
“For example, the fact that more than 80 percent of them were formed in the presence of water shows how important moisture is. This fact may explain why the Moon, Mercury, and even Mars do not come close to showing such mineral diversity.”
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