This astonishingly lightweight 18-karat gold nugget has a secret
One word: plastics!
It looks like gold. It can be polished like gold. It is gold, but it's also something more. Researchers at ETH Zurich university in Switzerland have created a lightweight nugget that is still 18-karat gold.
Typical 18-karat gold is an alloy of 75% gold and 25% of one or more other metals, such as copper or silver. This miraculous nugget uses plastics instead of metal for that 25%. This secret ingredient means scientists can create gold that weighs five to 10 times less than a traditional nugget. This could make wearing bling much less of a burden.
The team used protein fibers and polymer latex as a matrix and embedded gold nanocrystals to form the material, which looks just like regular 18-karat gold. What you can't see are all the invisible air pockets in the nugget.
A video from ETH Zurich shows what happens when the nugget is dropped on a hard surface. Spoiler: It sounds like plastic.
"This gold has the material properties of a plastic," said ETH Zurich materials scientist Raffaele Mezzenga in a release on Friday. The researchers said they can also create a type of "plastic gold" that mimics the metal's melting process at much lower temperatures than standard gold.
The team published a paper on its lightweight gold in the journal Advanced Functional Materials on Friday.
The gleaming material could be used to make lightweight jewelry, but is "also suitable for chemical catalysis, electronics applications or radiation shielding." This plastic gold appears to have a bright and shiny future ahead.
