Have a girlfriend? Wish to gift her diamonds? Get her the galaxy’s largest diamond. But you’d better carry a deep wallet, because this 10 billion trillion trillion carat monster has a cost that’s literally astronomical !“You would need a jeweler’s loupe the size of the Sun to grade this diamond!” says an astronomer.
Bill Gates and Donald Trump together couldn’t begin to afford it. I think you may be astonished why I mentioned “literally astronomical’.
“I am the richest”, says Cancri
A cosmic diamond was discovered by the scientist at Yale University in 2012. That’s not a diamond, it’s actually a planet. It was named 55 Cancri. An interesting question is that how it actually became a diamond? We know that, our scientists are in search of a planet like Earth for the past 10 years.
“It’s the mother of all diamonds!” says Metcalfe.
When 55 Cancri was first observed, they considered it as a planet of water like Earth. But later research proved that it is a clod of crystallized carbon 50 light-years from the Earth in the constellation Centaurus. (A light-year is the distance travelled by light in a year, or about 6 trillion miles.) It is twice the radius of Earth, eight times the mass, which was approximately 10 billion trillion trillion carats, or a one followed by 34 zeros .Oh man, if I own this, I would die in joy.
The planet has a surface temperature of 3,900 degrees Fahrenheit (2,150 Celsius), and its year lasts just 18 hours (as opposed to Earth’s 365 days) as it’s the innermost planet in the 55 Cancri system.
White dwarf is a term referring to the hot core of a star, which remains after the star has completely used up its nuclear fuel. It is mainly composed of carbon and covered by a thin layer of hydrogen and helium gases. Now a question will rise in you, has the sun reached a day for its doom? Yes! It has. Our Sun will become a white dwarf when it dies 5 billion years from now. Some two billion years after that, the Sun’s ember core will crystallize as well, leaving a giant diamond in the centre of our solar system.
“Our Sun will become as diamond that truly is forever,” says Metcalfe.
“The hunt for the crystal core of this white dwarf has been like the search for the Lost Dutchman’s Mine. It was thought to exist for decades, but only now has it been located,” says co-author Michael Montgomery (University of Cambridge).
Imagine a situation; you are out on a tread alone. A huge rock (a meteorite) is approaching nearer and you are safe by luck. On the next day, reading the newspaper you come to know that it’s not just a rock, but a diamond. Weird, isn’t it? If you identified it on the tread itself, what would have you done?
In 1888, Russian scientists discovered that a meteorite reaching the Earth which is iron and stony has the composition of diamond but in less proportions. Making fortune from these diamonds is a painstaking effort by trying to retrieve them from the meteorite material because the diamonds are really tiny, just a few nanometres in size.
They have been coined meteoritic Nano diamonds as MNDs. The small size makes MNDs interesting for a down-to-earth application in Nature Nanotechnology and demonstrate that even tiny MNDs can contain silicon-based luminescent defects (silicon-vacancy centres, SiVs) showing stable fluorescence in the red spectral range. The combination of these properties, the small size and bright fluorescence, makes MNDs ideally suited for biomedical imaging and fluorescence markers in life-science applications
Thief lights up
Interstellar Nano diamonds may even contain luminescent colour centres such as nitrogen vacancies (NVs), as inferred from the spectrum of the extended red emission band in planetary nebulae. Colour centres in these Nano diamonds might be created by incorporation of impurities from the gas phase or probably by ion implantation from high-speed particles.
The demonstration that Nano diamonds smaller than 2 nm (a few hundred carbon atoms only) can host colour centres with stable fluorescence comes as a surprise, as the stability of luminescent defects in Nano diamonds has been the subject of debate. Although NV centre luminescence has been observed in 5-nm man-made diamonds resulting from the detonation of explosives, the emission was not stable. On a more fundamental level, the tiny Nano diamonds are interesting because they are so small that lattice vibrations (phonons) are modified compared with their bulk counterpart due to finite-size effects.
Size matters when it comes to cell biology, where fluorescent Nano diamonds are considered a non-toxic and photo stable alternative to quantum dots as fluorescence markers. Here, the usual particle size for quantum dots or Nano diamonds is 20–40 nm. Such ‘big’ particles do still enter cells, although quite slowly, and if they are inside they are often trapped in vesicles far away from the interesting places. On the other hand, small Nano diamonds (5–10 nm) have been found to move freely in the cytoplasm, allowing their use as tracers or bio molecule delivery agents. But size alone is not sufficient: the small Nano diamonds still have to show fluorescence. Here MNDs with SiV emission stand out as they are the only isolated Nano diamonds smaller than 5 nm with stable emission. There is another property that puts Nano diamonds with SiV centres at the cutting edge: they have been proposed and recently used as fluorescent labels in biomedical imaging as their emission falls into the optical window of biological tissue, minimizing absorption and auto fluorescence.
In the light of these exciting perspectives one question remains: do you have to catch a meteorite to obtain Nano diamonds with stable fluorescence? Certainly not; there are encouraging steps towards production of artificial Nano diamonds of ever smaller dimensions, although the deterministic doping with the desired colour centre remains a major challenge. Every meteorite reaching the earth is a treasure.