DarkRange55
We are now gods but for the wisdom
- Oct 15, 2023
- 2,059
Rare earth elements (REEs) are not truly geologically rare. Even the least abundant, thulium, is about 125 times more common in Earth's crust than gold, while the most abundant, cerium, is roughly 15,000 times more common. The term "rare" refers less to absolute abundance and more to the difficulty of extracting them: REEs tend to be dispersed in very low concentrations, economically viable deposits are scarce, and they are notoriously difficult to separate from each other. By contrast, some metals outside the REE group, such as those in the platinum group, are genuinely rarer in Earth's crust than gold.
The origin of heavy elements. The Big Bang produced only the lightest elements—hydrogen, helium, and traces of lithium and beryllium. Heavier elements, including gold and platinum, were created much later in astrophysical events. Elements heavier than iron formed when atomic nuclei captured neutrons, followed by beta decays that converted some neutrons into protons. This process happens mainly in neutron star mergers and, to a lesser extent, certain types of stellar explosions. Once the neutron supply is exhausted, the unstable isotopes decay into stable or long-lived nuclides, leaving behind the cosmic abundance pattern.
It is not a question of chemical stability but of nuclear stability: iron and nickel are the most tightly bound nuclei, so heavier elements only persist where decay chains terminate in stable isotopes. Gold (Au, atomic number 79) sits in Group 11 of the periodic table, alongside copper and silver, and has only one stable isotope, Au-197. Platinum (Pt, atomic number 78) sits just to the left in Group 10, part of the platinum group metals, and has five stable isotopes: Pt-190, Pt-192, Pt-194, Pt-195, and Pt-196. That difference in isotopic diversity means there are more possible decay endpoints for platinum, while gold requires slightly more neutron captures to form. For those reasons, platinum is about 5–10 times more abundant than gold in solar abundance tables, which are widely used as proxies for cosmic averages.
On Earth, however, the balance looks different. In the crust, gold is slightly more common than platinum. This is not due to nuclear physics but geochemistry. Platinum is highly siderophile—"iron-loving"—and during Earth's formation most of it sank into the core. Gold, by contrast, is less strongly partitioned into iron and forms chemical compounds that are more easily concentrated in crustal ore deposits. The result is that at the surface, gold is more accessible than platinum even though in cosmic terms it is rarer. Local geological accidents, such as meteorite delivery and concentration processes, may also have tilted the ratio in Earth's favor.
Looking beyond gold and platinum, the rarest metals in Earth's crust include the platinum group elements (rhodium at ~0.0002–0.001 ppm, iridium and osmium at ~0.00005–0.001 ppm, ruthenium at ~0.001 ppm, platinum itself at ~0.0005 ppm) and rhenium (~0.0002–0.0007 ppm). All of these are significantly scarcer than gold at ~0.001–0.004 ppm. By contrast, metals like indium (~0.05–0.25 ppm) and tantalum (~1–2 ppm) are more abundant than gold in crustal rock, though often considered economically "rare" because they seldom occur in concentrated ores.
Minor variations exist in exact values across sources due to measurement methods
The US holds almost a trillion dollars worth of gold (8000 tonnes). China owns about a quarter trillion dollars in gold, etc.
It has value because the countries give it value by considering it to have value.
The 1929 stock market crash lasted 25 years.
But from 1980 to 2000 gold declined over 80%. It took until 2024 to reach a new high. If you bought in February 1980, you wouldn't have a positive return for 44 years. You only lost if you bought in 1980 really. If you had bought anywhere from 1970 to early 1979, was muted.
The origin of heavy elements. The Big Bang produced only the lightest elements—hydrogen, helium, and traces of lithium and beryllium. Heavier elements, including gold and platinum, were created much later in astrophysical events. Elements heavier than iron formed when atomic nuclei captured neutrons, followed by beta decays that converted some neutrons into protons. This process happens mainly in neutron star mergers and, to a lesser extent, certain types of stellar explosions. Once the neutron supply is exhausted, the unstable isotopes decay into stable or long-lived nuclides, leaving behind the cosmic abundance pattern.
It is not a question of chemical stability but of nuclear stability: iron and nickel are the most tightly bound nuclei, so heavier elements only persist where decay chains terminate in stable isotopes. Gold (Au, atomic number 79) sits in Group 11 of the periodic table, alongside copper and silver, and has only one stable isotope, Au-197. Platinum (Pt, atomic number 78) sits just to the left in Group 10, part of the platinum group metals, and has five stable isotopes: Pt-190, Pt-192, Pt-194, Pt-195, and Pt-196. That difference in isotopic diversity means there are more possible decay endpoints for platinum, while gold requires slightly more neutron captures to form. For those reasons, platinum is about 5–10 times more abundant than gold in solar abundance tables, which are widely used as proxies for cosmic averages.
On Earth, however, the balance looks different. In the crust, gold is slightly more common than platinum. This is not due to nuclear physics but geochemistry. Platinum is highly siderophile—"iron-loving"—and during Earth's formation most of it sank into the core. Gold, by contrast, is less strongly partitioned into iron and forms chemical compounds that are more easily concentrated in crustal ore deposits. The result is that at the surface, gold is more accessible than platinum even though in cosmic terms it is rarer. Local geological accidents, such as meteorite delivery and concentration processes, may also have tilted the ratio in Earth's favor.
Looking beyond gold and platinum, the rarest metals in Earth's crust include the platinum group elements (rhodium at ~0.0002–0.001 ppm, iridium and osmium at ~0.00005–0.001 ppm, ruthenium at ~0.001 ppm, platinum itself at ~0.0005 ppm) and rhenium (~0.0002–0.0007 ppm). All of these are significantly scarcer than gold at ~0.001–0.004 ppm. By contrast, metals like indium (~0.05–0.25 ppm) and tantalum (~1–2 ppm) are more abundant than gold in crustal rock, though often considered economically "rare" because they seldom occur in concentrated ores.
Minor variations exist in exact values across sources due to measurement methods
The US holds almost a trillion dollars worth of gold (8000 tonnes). China owns about a quarter trillion dollars in gold, etc.
It has value because the countries give it value by considering it to have value.
The 1929 stock market crash lasted 25 years.
But from 1980 to 2000 gold declined over 80%. It took until 2024 to reach a new high. If you bought in February 1980, you wouldn't have a positive return for 44 years. You only lost if you bought in 1980 really. If you had bought anywhere from 1970 to early 1979, was muted.
