I'm writing a book that's set on a planet very similar to earth, meaning it has all the same gravity, mineral compositions, and geologic features. With that in mind:

  1. What geological features are the best to mine/find what minerals? I.e. what terrain (low hills, inactive volcanos, sedimentary rock, new mountains, along tectonic plates) would important materials be found in? (the main ones I'm curious about are gold, silver, copper, iron, jade, and diamond).

  2. How close to the surface would/could these materials be? I.e. is it possible to find the materials listed above without mining for them? If so, under what circumstances would they be found (erosion, volcanic activity, etc.).

  3. How close could veins of certain materials be to each other? I.e. is it possible to have a mine that mines for iron, copper, and gold, or would there be regions in which people could only mine gold or only mine iron? If the latter is true, how close could these areas realistically be?

This is my first question, so feel free to correct the way I phrased things or ask for clarification. Thanks!

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    $\begingroup$ They're probably going to tell you that you're only allowed to ask one question, but i feel that this question is adequately constrained. In general, however, one question means one question. $\endgroup$ Jan 7, 2023 at 5:25
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    $\begingroup$ There are many geological features on Earth that are locally indicative of the presence of particular mineral. The features that indicate the presence of gold in Alaska are very different than those in Australia. Similarly the depth below the surface of mineral deposits varies depending on where you are on Earth. As for how close different minerals can be to each other, it wildly varies depending on where you are on Earth. Given the large variety of possible answers just on earth, how to you expect there to be a single specific answer to this question about some strange planet? $\endgroup$
    – sphennings
    Jan 7, 2023 at 7:30
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    $\begingroup$ Hello Cuttlefish and welcome to Worldbuilding! I hope that you will find your experience on this site both interesting and useful. You may want to take the tour and peruse the help center in order to become better acquainted with the rules and expectations of this site. In particular, what research have you done before asking this question? $\endgroup$
    – AlexP
    Jan 7, 2023 at 9:26
  • $\begingroup$ As far a distance between veins: it is entirely possible for them to overlap or even be the same vein. Lots (most?) metal ore is mixed thoroughly with other material, including other metals and minerals. For instance, a copper mine isn't going to extract only copper; what makes it a "copper mine" is that the ground is rich enough in copper to make it worthwhile to us to extract, and not more rich in something else (or it would be a "something else mine"). If it's sufficiently rich in multiple valuable materials, they'll happily collect it all and separate it out. $\endgroup$
    – Tom
    Jan 7, 2023 at 9:59
  • $\begingroup$ If the planet is no different from Earth, this question can (only) be answered with Earth geology. I'm not sure what the worldbuilding aspect is here. $\endgroup$
    – Cloudberry
    Jan 7, 2023 at 10:57

1 Answer 1



I think you can base your planet on Earth, and look this up in a geology book.

This is not me being pedantic about the definition of 'earth-like', but we have a very small statistical base to work on. Earth is earth-like. Mars is smaller, but may have been somewhat earth-like in the past. Venus is more earth-like below the surface. We seem to be continually surprised by the details we find on every planet, but the basic features on rocky planets do seem to have some constants...

They have a molten core. There are volcanoes. The molten core is bigger in the larger planets, but shrinks with age. Mars does not have tectonic drift like Earth, but it can still raise mountains and have rift valleys.

Mars had running water in the past, and recognisable sedimentary layers much like Earth. This will separate out ores in a similar way to Earth.


Water erosion can expose lower layers. We see this on Mars too. All of your materials have been found on or near the surface on Earth at one time, but this is pretty rare. People then dig down to get more of the same.


Some materials are found together because they are chemically similar. For example, every lead mine probably contains some silver. Some may be found together because they have similar densities so they settled out of running water together: see https://en.wikipedia.org/wiki/Ytterby

Basing your planet on Earth is not being unimaginative. The basic driving forces of vulcanism, erosion, and deposition ought to be much the same on your planet. If your inhabitants are in one place, then you could make it a place with deep valleys and heavily folded strata in the exposed sides, so there, so there is a better chance of finding something you want near to the surface.

We do not know how technologically advanced your miners are. Are they settlers from space, or have they always lived there? The backstory of how people learned where to look for stuff may be as important as how physically close it is. Hope this helps, anyhow.

  • $\begingroup$ I apologize for asking a question that could be answered by an earth-geology book. Thank you for your feedback! $\endgroup$ Jan 7, 2023 at 22:34
  • $\begingroup$ No apologies needed. If you saw the crazy things we have found lately, you could well think that just copying Earth is bo-oring. Why does Mars have perchlorate just beneath the surface? No-one really expected that. But it you get below the surface, the fundamentals of Earth-sized rocky planets are much the same as far as we know. $\endgroup$ Jan 8, 2023 at 10:04

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