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Earth is full of different minerals. Each patch of land, between plate tectonics and other forces, finds itself brimming with a variety of interesting and more importantly, different, minerals.

Does the same hold true elsewhere in the cosmos? The moon, Mars, Neptune, and other bodies have often been described in terms that would imply a strangely consistent landscape; a Mars perhaps coated from pole to pole with iron oxide. Do the other planets and moons share Earth’s mineral diversity, and if not, why?

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    $\begingroup$ You asked, and are getting answers, about mineral diversity. Please note that elemental diversity is different. Minerals present depend on the elements present, and the conditions (Temp, Pressure, elemental mixtures, etc etc) that they have been exposed to. $\endgroup$
    – simon at rcl
    Nov 26, 2020 at 16:11
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    $\begingroup$ @simonatrcl Great point. Is there a reason why Earth would have substantially greater elemental diversity? $\endgroup$
    – TheEnvironmentalist
    Nov 26, 2020 at 20:17
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    $\begingroup$ Elemental? No. Mineral? Sure. Active plate tectonics, liquid water and free oxygen come to mind as big sources (and drains) of minerals. But one the same scale that you talk about "Mars being coated from pole to pole with iron oxide", Earth is as well! And the same is true of aluminum and silicon oxides (on both Earth and Mars). Everything else is peanuts. The estimates of how much mineral diversity there is on Earth compared to Mars are tricky, but they're mostly in the range of one or two orders of magnitude, not five :) $\endgroup$
    – Luaan
    Nov 27, 2020 at 8:39

4 Answers 4

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We turn to Mars, which we have studied for decades now. And we do see plenty of mineral diversity on the surface of the Red Planet, it's not just rust by any means.

Curiosity's CheMin analyzer has studied the surface mineral composition of the Gale Crater. Quoting from this answer:

This diagram provided by Curiosity's CheMin analyzer (source) shows that the composition varies with depth inside the crater:

enter image description here

Not only do we see a wide variety of minerals also known on Earth, we see a suspiciously earthlike gradient in composition whereby the material near the top is dominated by weathering products (notably, iron oxidized to hematite and large amounts of clay) and the bottom consists of material that must have been more protected (mafic matter, magnetite; both of which would weather easily if exposed ot an oxidizing atmosphere), as if by water in an ancient lake.

In another example jarosite, a complex sulfate mineral associated with an extremely saline but still life-bearing environment on Earth, has been found by Spirit and Opportunity.

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    $\begingroup$ Granite has been found on Mars as well, and is a product of extended igneous processes that separate out the components of magma, recycle rock into magma, etc. The denser fractions that separated out must still be there somewhere as well, and might be useful ores. The moon on the other hand is pretty much just basalt and impact glass formed from basalt. And asteroids are generally very primitive material that hasn't changed much since it accreted, but Ceres stands out for its hydrothermal/cryovolcanic activity. $\endgroup$
    – Christopher James Huff
    Nov 26, 2020 at 4:21
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    $\begingroup$ It is worth noting that the presence of a handful of oxidated minerals also found on Earth does not mean that Mars has mineral diversity equal to the thousands of unique minerals known only to exist on Earth. Mars, as the only other rocky planet we have explored on the surface, and one believed to have previously held a chemically active atmosphere, will have more minerals on it than other less explored and less historied bodies. $\endgroup$
    – Anton Hengst
    Nov 27, 2020 at 2:31
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    $\begingroup$ However, stating that Mars has equal mineral diversity to Earth or that Earth's mineral diversity is not unique is entirely speculation. We have neither the evidence nor a reason to believe evidence exists that it is otherwise. $\endgroup$
    – Anton Hengst
    Nov 27, 2020 at 2:32
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    $\begingroup$ Or, one might say that Earth has a unique diversity of minerals because other planets/planemos have their own, different and also diverse, mineral profiles. $\endgroup$
    – Oscar Lanzi
    Nov 27, 2020 at 2:48
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    $\begingroup$ Knowledge of our planet's mineral diversity is the result of hundreds (thousands?) of years of geologic exploration. We can count the time spent on that task elsewhere in hours! Thanks, Oscar, for presenting the start of the actual data that we will need to answer this question. But I think it will be hundreds of years before we can answer this question. The answer depends not only on what we know about those bodies in their present condition, but also on what happened over the billions of years since they formed. $\endgroup$
    – John Pankowicz
    Nov 27, 2020 at 17:24
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They do not! The reasons for this are simple: minerals are semi-stable configurations of elements formed in certain pressure-temperature-redox conditions. A planet in the possession of active plate tectonics will also be in the possession of more extreme pressures and temperatures (not to mention introduces chemicals to such conditions that would not otherwise be present, like water and carbonates). Also, should be mentioned, Earth being such a large rocky planet (with such a large, active core) helps generate extreme PT conditions.

Also, life creates incredibly improbable redox conditions wherever it goes. An atmosphere flooded with oxygen? Crazy! Protons being ejected into the soil? Bizarre!

Suffice it to say that mineral diversity increased as life developed. The idea that life and minerals evolved together is known as "mineral evolution"... something of a misnomer, perhaps, but it gets the point across. Earth has lots of wild minerals because it has lots of wild life. New minerals are being discovered due to human activity as well; mining operations concentrates weird elements together & exposes them to warmth and humidity.

So, the answer is no--as far as we know (we have barely explored our own rocky planets & moons, much less other solar systems'), Earth's mineral diversity is unique.

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    $\begingroup$ Protons being ejected into the soil? What are you referring to? $\endgroup$
    – d-b
    Nov 26, 2020 at 8:36
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    $\begingroup$ Perhaps one of the more interesting examples of mineral evolution is Fordite - a substance that couldn't exist without the truly unusual-in-nature phenomenon of mass production of cars. $\endgroup$
    – Sebastian Lenartowicz
    Nov 26, 2020 at 9:21
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    $\begingroup$ @Joe Jobs I did not say life created oxygen, I said it created an oxygen rich atmosphere. Having large amounts of a highly oxidizing species available in gaseous form across an entire planet is remarkable. Anything else you think is wrong? $\endgroup$
    – Anton Hengst
    Nov 27, 2020 at 2:25
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    $\begingroup$ @d-b root processes of many terrestrial plants exude protons to swap for nutrient ions adsorbed onto clay particles. This is why many highly evolved plants acidify soil, as it increases uptake of phosphate and nitrogen species. $\endgroup$
    – Anton Hengst
    Nov 27, 2020 at 2:27
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    $\begingroup$ @JoeJobs: Your point of view is valid and an extremely interesting point of view, the subject of research. But this question specifically asks about the abundance and diversity of minerals, not elements. $\endgroup$
    – dotancohen
    Nov 27, 2020 at 11:17
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According to this dated but enjoyable Scientific American article https://sciences.ucf.edu/class/wp-content/uploads/sites/23/2020/01/Hazen-The-evolution-of-minerals-Scientific-American.pdf, Earth is likely unique in mineral count in our solar system. This is because of

  1. the pressure cooker effects of Tectonics,
  2. the solvent action of water, and
  3. the redox chemistry of life.

Bottom line: about half the minerals on earth would not be here without Life.

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  • $\begingroup$ Excellent succinct answer. $\endgroup$
    – Freddo411
    Dec 19, 2021 at 14:45
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We have a little bit of information about the Earth Moon and the planet Mars and very little bit about Venus, but nothing like the wealth of information about the Earth's minerals, more than 5000 known minerals. There may be unknown minerals very deep in the oceans or deeper than the deepest bore holes.

We may suspect the gas giants Jupiter, Saturn, Neptune and Uranus got no minerals at all in the upper gas layers.

Planets and Moons without water should have no minerals requiring water for the formation. There should be no minerals like coal or limestone requiring plants, animals, bacteria or free oxygen in the atmosphere. These kind of minerals should exist only on Earth.

But we don't know if there are minerals not found on Earth but on the icy moons existing only at very low temperatures. Or minerals that don't exist in an atmosphere with oxygen. Or minerals existing only at very high pressure deep in a gas giant.

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    $\begingroup$ I would count the ices on outer Solar System objects as minerals which are not in mineral form on Earth. Also, some objects farther outvtgan Earth contain salts that are relatively rare here, like ammonium salts on Ceres. $\endgroup$
    – Oscar Lanzi
    Nov 27, 2020 at 2:00
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    $\begingroup$ Also, it's not like minerals come with a unique identifier saying "this is silica!". The way we classify minerals is useful, but ultimately arbitrary - we could easily classify the same set of minerals as a hundred different minerals or a thousand. Categorization is something humans (and probably other animals) love to do, but it's a pale shadow of the complexity of the real world. $\endgroup$
    – Luaan
    Nov 27, 2020 at 8:45
  • $\begingroup$ @Luaan That's a fantastic point. If I could upvote twice I would $\endgroup$
    – TheEnvironmentalist
    Nov 27, 2020 at 20:44
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    $\begingroup$ There are some of variations of quartz crystals looking very different like citrine, rose quartz, amethyst, smoky quartz, milky quartz. But they differ only in small impurities. $\endgroup$
    – Uwe
    Nov 27, 2020 at 21:04
  • $\begingroup$ @Luaan - well, silica and other primary mineral types ARE readily identifiable but yes, there are all the mixtures and minerals with series of substitutions of elements, metamorphoses and other spectra of variation with near infinite graduations. There are minerals formed in anaerobic conditions on Earth and hydrated minerals found in meteorites. The relative abundance and formation of ore bodies is going to be very different even where the minerals can be present. $\endgroup$
    – Ken Fabian
    Dec 21, 2021 at 0:45

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