Here is a conversation I have almost daily at my desk:

Passer-by notices cube: "What is that, it looks cool/awesome!"
Me: "It's a solid tungsten cube"
Passer-by tries to pick it up: "What the #$%# why is it so @#$@ heavy!!???"

Why Tungsten?

  • 70% denser than lead
  • Denser than Uranium
  • Nearly impossible to melt
  • 4x harder than Titanium
  • 19x denser than water
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. 
Tungsten is an extremely rare element (only 100 parts per billion in the earth's crust).