I saw an interesting post on Reddit related to worldbuilding and I thought I'd reproduce it here for the fediverse. It's from /r/Userfaulty and it's about where natural resources would appear normally in the world. It might not be completely accurate but it's a great start and inspiration.

A Guide to Placing Resources on Fictional Worlds

Resource

I recently watched a great video on youtube by Artifexian where he showed how to place Fuels and Metal Ores on a fictional world. But I was left in a lurch. What about stones? What about valuable gems? What else should I at least make a note of that could be of strategic importance? Well...I did the digging and below is my abstract, I haven't taken geology classes in 20 years, guide to placing resources on your fantasy world maps. If you find something below that I grossly misjudged then let me know and I will try to fix it but keep in mind that these don't need to be accurate to the real world. They are just suggestions to help the worldbuilder that just wants help in placing it in a somewhat believable area. I tried to be as accurate as I could. The below locations will contain the highest quality of the materials or will be the easiest to find for your early hunter gatherer societies. edit Added more wood types for bows and arrows. Included areas for Iron. Added Clay and Tar.   Fuels

Coal remains of ancient tropical and subtropical swamps that then become compacted over lots of time remains become Peat then when buried further becomes Lignite Lignite buried further becomes more concentrated and becomes Bituminous Coal Then becomes Anthracite

Place Coal in areas that were low-lying tropical and subtropical swamps Higher quality coal in foothills of mountain belts that formed in those regions do not place Coal in interior of mountain chains

Graphite will form in interior of mountain chains instead of coal

Place Peat reserves in modern day low-lying wetlands

  Oil & Gas derived from remains of ancient plankton remains fell to bottom of ocean buried and compacted to form Shale Shale then becomes Oil Shale Oil Shale at greater depths becomes Oil and Natural Gas Oil will try to escape through the water table to the surface forming Gas/Oil Seep

Place Oil in locations that were once shallow tropical seas and lakes also normally forms along tectonic plates

  Metal Ores

Deposits of Copper forms around volcanic plate boundaries Copper, Copper-Gold, Copper-Molybdenum, or Molybdenum will also form near Volcanic Hotspots These will contain minor amounts of Lead, Zinc, Silver

Place a couple Tin-Tungsten deposits here too

Gold Place near the Copper deposits but still close to volcanic active plate boundaries

Place Gold with minor amounts of Silver and Copper Farther out place Gold with minor amounts of Silver, Lead, and Zinc Farther out place Gold with Minor amounts of Silver and Mercury Farther out place Iron-Copper-Gold deposits, will become sources of Uranium

Place Nickel-Copper and PGE-Chromium (Platinum, Palladium, Rhodium, Ruthenium, Osmium, Iridium) in the middle of stable plates

Place Iron around old mountain chains (this can be lone sections of hills or mountain bands that are not near active volcanic boundaries). Also can be placed around swamps and marshlands. Iron can be found almost everywhere but these locations will contain highest quality or be the easiest to find for early hunter gather societies.

Place Lead-Zinc-Silver in sedimentary basins along outskirts of coasts (fairly uncommon)

Place Aluminium in rain forests or very wet regions

Place some secondary deposits of all ores downstream from mountain deposits or inland a ways from the main source

  Stones

Ancient Chalk beds formed on the floor of ancient seas.

The Chalk later solidifies into Limestone. Can be placed where hills meet grasslands in non wet areas.

Flint (also called Chert) forms as lumps between layers and in cavities left in the sea floor in these Chalk beds.

Marble is formed from Limestone that has been subjected to intense heat and pressure. Marble will be placed near mountain ranges.

Jade is placed not too far inland along ancient or current convergent plate boundaries that occur or occurred along a coastline. They will be located on the steeper parts of drainage basins where erosion reveals the uplifted mineral. Was also used as stone age tools.

Obsidian is formed when water flows over volcanic lava to cool it rapidly. Placed near volcanic plate boundaries that no longer have large amounts of water. Water breaks down obsidian over time.

Granite is formed when molten rock is slowly cooled. It forms the bottom layer of all land continents. Placed along two land type convergent boundaries on the uplifted side where it is raised to the surface, making quarrying easy.

Sandstone is formed when sand is deposited in large quantities and under goes large amounts of pressure, heat, and drainage causing the sand and other minerals to "cement" together. Placed near ancient drainage basins that deposited sand from deserts or beaches, or alternatively where hills or mountains meet a dry desert.

Clay can be placed on hillsides, on lake and sea bottoms or on shores, and near volcanic hot spots that heat a water source.

  Gems

Agate place near ancient volcanic flows that met active drainage basins.

Amber occurs in ancient pine type forests then carried by rivers and tides to deltas in coastal regions, where they were buried over time.

Amethyst can be placed where ancient lava would flow near an iron deposit.

Aquamarine normally found in the interiors of tectonic plates and located near Granite and contains a Tin - Tungsten deposit in the same water shed.

Carnelian normally located near ancient volcanic plate boundaries with iron deposits and then are washed down to river beds in current times

Citrine is formed by heat treating purple Amethyst or can be found where Amethyst has been naturally heat treated

Coral is normally found between the Tropics of Cancer and Capricorn (the equator to the lower and upper temperate zones) but can be farther out where warm currents flow out of tropics.

Diamonds will go in the middle of stable tectonic plates (near Nickel-Copper and PGE-Chromium, make them rare)

Emeralds almost the same as an Aquamarine but when a PGE-Chromium deposit is in the same water shed.

Garnets can be found in Granite but is also found where two tectonic plates converge.

Jade is placed not too far inland along ancient or current convergent plate boundaries that occur or occurred along a coastline. They will be located on the steeper parts of drainage basins where erosion reveals the uplifted mineral.

Jasper is formed when ancient volcanic flows possibly met with ancient sea beds that then get reburied, are relifted, and then are washed down to river beds in current times.

Jet is similar to coal but is formed differently. Coal is from ancient wooded swamps, Jet is from wood material being washed into a body of water, becomes waterlogged, sinks and is covered by organic rich sediment.

Lapis Lazuli can be placed in high naked mountain valleys along plate boundaries and is somewhat rare. formed when underground magma contacts limestone.

Obsidian is formed when water flows over volcanic lava to cool it rapidly. Placed near volcanic plate boundaries that no longer have large amounts of water. Water breaks down obsidian over time.

Onyx is formed in the same way as Agates and can be placed in the same manner.

Opals are placed near or in sandstone deposits.

Pearls can form in any mollusk like creature in any body of water.

Peridot/Olivine is normally found around active lava flows near tectonic hot spots or where lava has fallen during a pyroclastic blast around an erupted volcano and cooled quickly.

Rubies are placed near convergent plates that has no iron but has trace amounts of Aluminium and Chromium. They are extremely rare. They should be placed in stream beds or watersheds leading away from the creation site.

Sapphire is the same as Rubies but has trace amounts of Titanium instead of Chromium.

Shells are found in tropical coastal areas with shallow tide pools.

Topaz can be placed near volcanic convergent plate boundaries.

Tourmaline can be placed similar to Granite. Can also be found in stream bed long distances from the source deposit.

Turquoise is is formed when copper deposits are transported through a watershed that contains aluminium deposits in arid environments.

  Wood

There is a large amount of wood and it would take much longer than I want to discuss all the types of wood. You should keep in mind at least the following historic common uses for wood but its up to you:

Dyes - Brazilwood

Paper - Mulberry, Bamboo, Beech bark was also used as a writing tablet

Glassworks - Beechwood

Shipbuilding - Elm for capstans and mastheads. Larch and fir for internal planking, masts, and spars. Oak for hulls. Walnut for rudders.

Weapons - Ash for spear shafts. Hickory for weapon hafts. Osage, Bamboo, Ash, Black Locust, Oak, Maple, Yew, Elm, or any flexible hardwood or animal horns for bows. Pine and Cedar is common for Arrows. Walnut for gun stocks.

Bridge Pilons - Alder

Construction - Sycamore, Oak, Bamboo, Poplar, Hickory

Forges for Iron and Bronze - Charcoal, Coal, Coke, Any abundant wood will do

  Oils

Olive Oil

  Glues

Pitch, Tar, Bitumen, Asphalt, Resin - Pine, Petroleum, Coal Tar, or Plants. Can be collected from Charcoal production, Tar pits where Oil Seeps occur. Resin is made from plants. Bitumen and Asphalt is Petroleum (crude Oil).

  Whales   Furs   Spices   Salts

can be placed along low-lying ocean beaches or inland in deserts that formed from evaporated inland seas

  Sources

Most of the information was gathered from these sources: https://www.youtube.com/watch?v=b9qvQspSbWc&t=582s by Artifexian

http://www.stoneagetools.co.uk/what-is-flint.htm https://geology.com/gemstones/jade/#geology http://dianahurwitz.blogspot.com/2018/03/worldbuilding-gemstones.html https://www.getty.edu/publications/ambers/intro/4/#:~:text=Amber%20is%20formed%20from%20resin,hardens%20and%20forms%20a%20seal. https://sciencing.com/how-amethyst-geodes-formed-4913351.html https://www.minerals.net/mineral/amethyst.aspx https://www.gemrockauctions.com/learn/technical-information-on-gemstones/what-is-aquamarine-made-of#:~:text=Aquamarine%20Formation,magma%20which%20forms%20the%20gemstone.&text=Almost%20all%20aquamarines%20are%20formed,world%20where%20there%20are%20mountains. https://en.wikipedia.org/wiki/Pegmatite https://en.wikipedia.org/wiki/Beryl#:~:text=While%20gem%20beryls%20are%20ordinarily,miarolitic%20cavities%20of%20the%20rhyolite. https://www.gemselect.com/english/gem-info/carnelian/carnelian-info.php https://coral.org/coral-reefs-101/coral-reef-ecology/geography/#:~:text=Most%20reefs%20are%20located%20between,in%20Florida%20and%20southern%20Japan. https://www.ga.gov.au/education/classroom-resources/minerals-energy/australian-mineral-facts/garnet#:~:text=Most%20garnet%20forms%20when%20a,and%20cause%20minerals%20to%20recrystallise.&text=Garnets%20can%20also%20be%20found,such%20as%20granite%20and%20basalt. https://www.minerals.net/gemstone/chalcedony_gemstone.aspx https://geology.com/gemstones/jet/#:~:text=Jet%20does%20not%20form%20in,degraded%2C%20and%20heated%20in%20isolation. http://www.gemstones-guide.com/Lapis-Lazuli.html https://nature.berkeley.edu/classes/eps2/wisc/Lect16.html https://en.wikipedia.org/wiki/Pearl https://www.gemselect.com/other-info/about-peridot.php https://geology.com/gemstones/ruby-and-sapphire/