SAD LOVE QUOTES: Diamonds aren't forever: Earth's hardest natural material 'evaporates under exposure to light'

Tuesday, July 19, 2011

Diamonds aren't forever: Earth's hardest natural material 'evaporates under exposure to light'

Last updated at 5:09 PM on 19th July 2011

It seems Shirley Bassey got it wrong when she sang Diamonds Are Forever.

For scientists have discovered that Earth's hardest natural material evaporates under exposure to light.

A rock was placed under intense light pulses in the UV-C band - the harsh ultraviolet rays filtered out by the ozone layer - and small pits in the diamond surface were visible after only a few seconds.

Vulnerable: Scientists placed a rock under intense light pulses in the UV-C band and small pits in the diamond surface were visible after only a few seconds

Lead researcher Richard Mildren, from Macquarie University Photonics Research Centre, said: 'Although this type of light-induced evaporation has been observed in some materials, this is the first time it's been shown to occur for diamond.'

The rate of mass loss in the diamond fell notably for lower light levels but the etching process still continued - albeit at a slower and slower pace, Professor Mildren said.

But before diamond lovers around the world start to panic, he is quick to note that the rate of evaporation is very small and not noticeable under normal conditions.

In fact, even under very bright UV conditions, such as intense sunlight or under a UV tanning lamp, it would take approximately the age of the universe - about 10billion years - to see an observable distance, he said.

The rate of mass loss in the diamond fell notably for lower light levels but the etching process still continued - albeit at a slower and slower pace

The findings not only provide clues about the long-term stability of diamonds, but also have broad implications for future research.

Professor Mildren said: 'It's a very practical discovery and we are now looking at how we can exploit this.

'If we can make structures in the diamonds that enable us to control the position of the light within a very narrow filament in the diamond, that's the first step to making smaller and more efficient optical devices such as those used in quantum computing and high performance lasers.'

The discovery may also have implications as far reaching as the prospects for finding diamonds on the surface of other planets.

The study is published in the journal Optical Materials Express.