Researchers have figured out a way to make diamond aerogel. The aerogel is only 40 times as dense as air. Someday, it may coat the windows, the TV, and the inside of a person's body.

There are plenty of things out there that are shiny, but diamonds have occupied an enduring place in cultural history. At first this was because they were hard. Although it's easy to destroy other gemstones, diamonds are tougher to demolish, don't tarnish, and so can be worn with greater regularity than other jewelry. The particular hardness of diamonds also had industrial uses. Artificial diamonds helped drill bits and saw blades move through materials faster. Upon more study, scientists discovered new characteristics of diamonds - including the fact that they, like water, grow less dense when they freeze. This means that diamond oceans (such as those that might exist on Neptune) could have diamond icebergs floating in them.

Recently scientists have managed to construct the least-dense diamond structure ever made.


Aerogels are some of the least dense materials known to science. The lightest of them is only twice as dense as air. Usually they're made by suspending the aerogel particles in a liquid until they form a structure. Once they have solidified, the liquid is drained away, leaving the gel behind. The gel is so light that it's often referred to as 'frozen smoke'. The fact that these gels are mostly nothing makes them amazing insulators. Blow torches can be held to the bottom of aerogels while substances on the top remain unheated. They also block out acoustic and electrical signals.

To make a diamond aerogel, a carbon aerogel is constructed, and any spaces in the gel are pumped full of neon gas. The gas supports the structure and keeps it from collapsing when the scientists hit the carbon structure with everything they've got. The aerogel is compressed in a diamond-lined cell while being heated with high-intensity lasers. The combination of the heat and pressure change the pliable carbon to diamond, while keeping the structure.


This gel can be molded like plastic, is completely transparent, and is made up of diamonds smaller than a quarter of the wavelength of violet light. Because it doesn't react with many elements, it's biocompatible. This diamond matrix can be used to coat structures in the human body. Because it's transparent, it can be overlaid onto glass or clear plastic, creating tough but well-insulated windows and instruments for spacecraft. Because diamonds give off electrons, it can be used in ultra-light, ultra-tough quantum computers.

It just has to get a little bigger, first. So far the samples of this new gel are only about 200 microns wide. Still, its a potentially useful substance, and it's the most low-density diamond ever created. Way cooler than an engagement ring.

Via io9 and PNAS.

Photographs of aerogel via Radok.