Answer: Gold

Malleability, as a physical property of metals, is used to describe a given metal’s reaction to compressive forces. A metal with low malleability, like tungsten, will shatter when exposed to compression. A metal with high malleability, like lead, will deform when compressed.

Among all metals, gold is the most malleable. An avoirdupois ounce of pure gold can be compressed into an incredibly thin sheet that covers 300 square feet. Gold can be hammered so thin that the resulting gold “leaf” is semi-transparent and light (appearing greenish-blue) can pass through the lattice of gold atoms.

It is because of this extreme malleability that gold has been used for so many applications throughout history ranging from decorative (like ornate picture frames covered in a fine layer of gold leaf) to the practical (like the layer of reflective gold coating on the sun visors of astronauts’ helmets or, as seen here, on one of the James Webb space telescope’s mirrors).