There's no single "most expensive item" as it depends on definition (man-made, natural, substance, art), but top contenders include Antimatter (trillions per gram), the International Space Station (ISS) (over $100 billion for the project), the History Supreme Yacht ($4.8 billion), and artworks like Da Vinci's "Salvator Mundi" ($450.3 million). For a natural object, the asteroid 16 Psyche is valued in the quadrillions, while nitrogen atom-based fullerenes are incredibly costly per gram for scientific use.
From Antilia to Beverly Hills House: Here are top 10 most expensive things on Earth
The most expensive man-made object is the International Space Station (ISS). Its final cost will be over $100 billion (£66.7 billion).
Antimatter is the most expensive substance on Earth, costing around $62.5 trillion per gram. It consists of particles with opposite charges to those in normal matter. When antimatter meets matter, they eliminate each other, releasing vast amounts of energy.
16 Psyche is the Most Expensive Thing in the Universe. An astroid named 16 Psyche, after Cupid's wife, was found to be made almost entirely of iron and nickel. That means, in current US markets, 16 Psyche is worth somewhere around $10,000 quadrillion (the world's economy is around $74 trillion).
The most expensive thing in the world made by humans is International Space station.
The rarest thing to have ever existed in the universe is likely the first particles or moments of existence following the Big Bang. This includes phenomena like primordial singularity, quark-gluon plasma, or the extremely short-lived inflaton field responsible for cosmic inflation.
Found at a rate of only 1 part per 250,000 in the Earth's crust, gold is extremely rare. Some platinum group metals like rhodium are both rarer and more valuable than gold. On this page, learn more about how gold's rarity stacks up to other precious metals.
Antimatter, valued at $62.5 trillion per gram, is the world's most expensive substance, created atom by atom in the CERN Large Hadron Collider, a 27 km ring operating near absolute zero to accelerate particles to 99.99% the speed of light.
Could a toy that you own be worth lots of money in the future? If you think so, then hold on to it - as an old Star Wars action figure of Boba Fett has just fetched a record $1.342 million (£1.04 million), making it the most expensive toy ever sold at an auction.
7 Priceless Things
What many don't realize is that scorpion venom is the most expensive liquid in the world. One liter can be sold for around $10 million — and it provides an immediate benefit to humans.
The 15 Most Expensive Cars in the World
About 95% of the universe is "invisible" because it's composed of dark matter (around 27%) and dark energy (around 68%), which don't emit, absorb, or reflect light, unlike the normal matter (stars, planets, us) that makes up the visible 5%. Dark matter's presence is inferred through its gravitational pull on visible galaxies, while dark energy is a mysterious force causing the universe's accelerated expansion.
"As soon as antimatter touches matter, it blows up," says ALPHA collaboration member and UC Berkeley plasma physicist Joel Fajans. The combined mass of the matter and antimatter is transformed entirely into energy in a reaction so energetic that "explosion" doesn't do it justice. Scientists call it an "annihilation."
If you invested $1,000 in gold 10 years ago (around late 2015/early 2016), your investment would likely be worth significantly more today (late 2025), potentially in the range of $2,000 to over $3,000, reflecting substantial price appreciation, though less than the S&P 500 but outperforming during certain periods of market stress, acting as a hedge against uncertainty, with returns varying based on exact entry/exit points and premiums/spreads.
The rules do vary depending on where in the states you are planning to search for gold but, largely, as long as the use is recreational and you're not using any sluices or high-powered tools, any gold findings should be yours to keep.
The Rarity of Pure Gold
Gold that is 100% pure is rare to find, so more often than not this type of gold is actually 99.9% pure - hence 999 gold. Gold only makes up 0.0000004% of the Earth's crust - making it relatively scarce, especially among other metals used for jewellery such as silver.
Together, dark energy and dark matter make up 95% of the universe. That's almost the whole universe! That only leaves a small 5% for all the matter and energy we know and understand.
Return to the Moon
Artemis II, scheduled for launch between February and April sees the return of the first people to the Moon since Apollo 17 in 1972. Three American and one Canadian astronaut will orbit the Moon on a 10 day journey that lays the foundation for lunar landings in the coming years.
The Vaquita (Phocoena sinus), a small porpoise from the Gulf of California, is widely considered the world's rarest animal, with only around 10 individuals left, pushed to extinction by illegal gillnet fishing for other species like the totoaba. Other contenders for rarest include the Northern White Rhino (only two females remain) and the elusive Saola (Asian Unicorn), though population numbers for many extremely rare animals are uncertain.