Diamonds are the hardest, but evaporate under exposure to light

in technology

A new study shows that even the earth's hardest naturally occurring material, the diamond, is not forever.  The scientists have now discovered that diamonds evaporate under exposure to light.

Diamond is the hardest natural material known, where hardness is defined as resistance to scratching. It can be scratched only by other diamonds.  This hardness makes it suitable as a gemstone.

The  paper was published in the US journal Optical Materials Express this week by Richard Mildren and his colleagues from the Macquarie University Photonics Research Centre.

Diamonds are the hardest, but evaporate under exposure to light

"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," Mildren said.

The diamonds were exposed to 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. 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, 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 10 billion years - to see an observable distance, he said.

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

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

"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, Mildren said.

Source article: Characteristics of 2-photon ultraviolet laser etching of diamond. R. P. Mildren, J. E. Downes, J. D. Brown, B. F. Johnston, E. Granados, D. J. Spence, A. Lehmann, L. Weston, and A. Bramble,  Opt. Mater. Express 1 (2011)  576-585

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i knew that diamond is the hardest form of carbon. But this news is really amazing for that this hardest form evaporates under exposure to light. Really amazing.

I can remember taking an

As a child, I would raid my mom's jewelry box looking for diamonds. To the thrill of the mirrors in the house, it turned out my mom did not possess any diamond jewelry. While my childhood "mining" days were not fruitful, the scientific use of diamonds is what most piques my interest as an adult. Thus, to hear that this discovery may be a push in advancing high tech fields is very exciting.