Most expensive thing in the world: What qualifies as the most

What qualifies as the most expensive item in the world in 2025? From space-age engineering to crown jewels, blue-chip art, and ultra-rare automobiles, this definitive guide ranks the top 20 and explains why certain creations command sky-high price tags. Apr 14, 2025 · BBC Science Focus compiled a list of the most expensive materials, including antimatter at $59.8 trillion per gram and nitrogen atom-based endohedral fullerenes at $134 million per gram. Californium-252, used in nuclear reactors, costs $25.6 million pe... Sep 21, 2025 · From billion-dollar yachts to diamond watches and rare art, explore 15 of the most expensive things ever purchased by the world's wealthiest people Humanity has poured vast fortunes into building scientific marvels, engineering mega-projects, ultra-luxury collectibles, and priceless artworks. This ranked list explores the most expensive objects ever made, spanning space stations and dams to yachts, watches, and paintings.