The periodic table, by origin
118 ELEMENTS · 7 PROCESSES · 90 OF THEM FOUND ON EARTH
Each square carries the colour of the process that fused most of it.
ORIGIN SHARES ARE MODELLED SOLAR-SYSTEM MATERIAL, AFTER Johnson 2019 · ABUNDANCES CRC HANDBOOK · WHERE THESE NUMBERS COME FROM
Every atom heavier than lithium was assembled inside something. Fusing hydrogen into carbon takes a star; making gold takes two neutron stars colliding; making technetium takes a laboratory. So the table above is coloured by the process rather than by the chemistry — the same 118 squares a chemistry class uses, asked a different question.
90 of them have a natural supply worth the name. The other 28 are laboratory products: a handful of them, plutonium among them, turn up in uranium ore in quantities measured in atoms, and not one has a reservoir anybody could mine. Nothing made enough of them to outlast the four and a half billion years since this planet formed.
The three buttons above the table ask three different questions of the same 118 squares. Only the first is a physical measurement; the other two are groupings, and they are described as such below.
- WHERE IT WAS MADE
- Each square carries the colour of the process that fused most of it.
- WHERE IT LIVES
- Where the element is concentrated now. Pick a reservoir to isolate its chemistry.
- HOW EARTH GOT IT
- The route each element took to this planet — and which ones never took one.
A square is lit for a category if any of its share came from there. Gold is 95% neutron-star merger and 5% dying low-mass star, and isolating either one lights it.
- BIG BANG FUSION
- Fused in the first three minutes, while the whole universe was hot enough to be a fusion reactor. It made hydrogen, helium and a trace of lithium, and then it stopped — there is no stable nucleus of mass 5 or 8 to build through.
- COSMIC-RAY FISSION
- Not built up but broken down: a cosmic ray hits a carbon or oxygen nucleus drifting between the stars and shatters it. Lithium, beryllium and boron are almost the only elements stars destroy faster than they make.
- DYING LOW-MASS STARS
- A star of a few solar masses, near the end, grows a layer where nuclei catch neutrons slowly enough to decay between captures. It builds heavy elements one step at a time and then sheds them as a planetary nebula.
- EXPLODING MASSIVE STARS
- A star above about eight solar masses fuses its way to iron, fails, and collapses. Nearly all the oxygen in the universe — and most of the neon, magnesium and silicon — is the ejecta of that failure.
- EXPLODING WHITE DWARFS
- A white dwarf pushed past its limit by a companion detonates and burns most of itself to iron-group nuclei. These are the type Ia supernovae, and they are where a majority of the iron in your blood came from.
- MERGING NEUTRON STARS
- Two neutron stars spiral together and throw off a tenth of a solar mass of free neutrons. Capture is faster than decay there, so nuclei climb to gold, platinum and uranium in under a second.
- MADE BY HUMANS
- No natural supply on Earth at all. These exist because a reactor or an accelerator made them, and most of them exist for less than a day.
The second and third colourings are editorial. Nothing in the literature assigns each element one reservoir or one arrival route — every element is in every reservoir at some concentration, and most arrived by more than one path. What is grouped here is the dominant case, and the value of the grouping is the pattern it exposes: the platinum-group metals share a route to Earth that nothing else on the table shares, and it is the reason they are minable at all.
- STARS
- Held in stellar interiors and atmospheres, where it is fuel or ash.
- ROCKY PLANETS
- Locked into rock and metal — crust, mantle and core.
- GAS GIANTS
- Kept in the deep envelopes of the giant planets, which no rocky planet could hold.
- ASTEROIDS
- Concentrated in undifferentiated small bodies that never melted and sank their metals.
- COMETS AND ICES
- Frozen into the volatile bodies of the outer system.
- INTERSTELLAR MEDIUM
- Dispersed in gas and dust between the stars, in grains or as free atoms.
- NEBULA ACCRETION
- Condensed out of the solar nebula and accreted with the bulk rock and metal, 4.57 billion years ago.
- VOLATILE DELIVERY
- Too volatile to condense where Earth formed. It arrived later, carried in by water-rich asteroids and comets.
- LATE VENEER
- Arrived after the core had formed and swallowed the metals already here — a thin late coat of asteroid material that is why these are minable at all.
- MADE ON EARTH
- Not delivered. It is generated in place, by heavier elements decaying inside the rock.
- NEVER ARRIVED
- Never delivered and not made here by nature. It exists only where somebody makes it.
Atomic numbers, symbols, names and standard atomic weights are IUPAC’s. A weight printed in brackets is not a weight: the element has no stable isotope, so no standard atomic weight exists and the figure is the mass number of its longest-lived one.
The origin shares are the fractions of solar-system material each channel is calculated to have produced, following Johnson 2019 and the yield surveys behind it. They are model output, not measurement, and they are rounded to a few per cent here because that is roughly how far apart two groups running the same channels land on the heavy end. The split of the rapid neutron-capture elements between merging neutron stars and rare supernovae is an open question; this table gives the mergers the larger share, which is where the evidence currently points and not where it has settled.
Crustal abundances are the CRC Handbook of Chemistry and Physics’ values for continental crust, in milligrams per kilogram. They span nineteen orders of magnitude, which is why the bar that draws them is logarithmic and says so.
The drawing of the atom is a Bohr model and is not to scale in any respect. It counts honestly — the protons, neutrons and electrons on it are the right number, and the electrons are distributed by shell — and it claims nothing else. Real atoms have no orbits, and a real nucleus is about a hundred-thousandth of the width of its electron cloud. How the catalogue’s own numbers were made is a separate document, and none of the figures on this page come from it.