Tungsten is an extremely rare element (only 100 parts per billion in the earth's crust). "The density of the Tungsten cube makes for a pleasing contrast with the immaterial nature of cryptocurrency and NFTs." -- James Vincent
Tungsten has the highest melting point of any element. In fact, you can't easily build a container to melt it. You have to resort to expensive powder compression methods to form it. The manufacturing process is truly amazing. A pressure of 60 tons per square inch is used to create the cube in a giant steel press.