The Incredible Tale of Gravity Defying Gold

Considering that gold has a very high density, and is one of the heaviest metals per volume in the world, the fact that researchers at ETH Zurich have succeeded in creating gold aerogel so light that it can float is quite an accomplishment!

Aerogels, also called ‘frozen smoke’ are produced synthetically with solids and a high porosity. Since the voids between particles fill with air, they have very low density.

Although at first glance, this particular aerogel appears as a sprayable gold ingot, it is in fact a thousand times lighter. The material, which is a type of rigid foam, is actually lighter than water – its density is close to that of air. Gold aerogel can also be freely shaped, even with bare hands!

Interestingly, this new spray has quite a bit of intrinsic value, as it is composed of 83% pure gold. The remainder consists of air bubbles and a little bit of milk (that is not a typo – yes, milk).

The process used to create the gold foam makes use of heated milk proteins, which form miniature amyloid fibrils. These are then placed in a solution containing positively charged ions of gold. After a period of evaporation, the fibers are arranged into a 3D structure, around which crystallized gold forms a kind of ‘grid.’

In addition to perhaps leading to the creation of super-lightweight jewellery, gold aerogel has numerous potential engineering applications. Its usefulness is primarily due to its catalytic properties and thus its ability to carry a current, but this requires subjecting the gel to high pressure so that the gold particles come into contact with one another.

Mining Legislation that is Out of this World

Last week, a momentous piece of legislation was unanimously passed by the US congress. Known as H.R.2262 — SPACE Act of 2015, this bill both acknowledges celestial bodies as a potential, exploitable source of resources, and seeks to begin to regulate any future endeavors to extract minerals from them. Eric Anderson, president of Planetary Resources (a company which is seeking to begin mining asteroids) believes that this draft law “establishes the same supportive framework that created the great economies of history, and it will foster the sustained development of space.”

Asteroids, which are believed by scientists to be packed with a wide variety of useful minerals (including iron, nickel, gold, silver, platinum, etc.) have for a number of decades been the subject of viable commercial expansion into outer space. The purity of the ore deposits, and the sheer number of ‘planetoids’ flying around our solar system have resulted in the potential space mining industry being valued in the trillions of dollars.

With president Barack Obama poised to sign the legislation into law later this month, U.S Congressman Bill Posey made a statement that the set of regulations represents a “landmark for American leadership in space exploration.” For his part, Anderson believes that “many years from now, we will view this pivotal moment in time as a major step toward humanity becoming a multi-planetary species.”

The limitations of the bill are immediately obvious – the legislation will only apply to US citizens and firms operating out of the USA, but it is the spirit rather than the word of the law which is important. The fact that this bill has come into existence at all is a symbol of the great strides that mankind has made in the field of space exploration. Also of note is the inclusion of a clause which clearly states that the ruling does not allow for the assertion of “sovereignty or sovereign or exclusive rights or jurisdiction over, or the ownership of, any celestial body.”

Scientists Discover Brilliant New Cancer Detection Method

Researchers from the University of Sydney have announced that diamonds might well be the future in cancer detection and treatment. The basic premise of the new technique is based on the same principle that has made diamonds a favourite in jewellery the world over – namely that when they catch light, they sparkle.

When placed in an MRI machine, they ‘light up’ on the readout as they are being bombarded by rays. When synthetic nano diamonds are then attached to compounds known to adhere to cancers, they will clump up when injected into an organism, thus revealing the location of even the earliest stage tumors.

Though theoretically impeccable, the method has yet to be tested on animals – a stage of research that the team is currently seeking permission to enter. Hopes are high, with lead researcher Professor David Reilly being quoted as saying that “this is a great example of how quantum physics research tackles real-world problems, in this case opening the way for us to image and target cancers long before they become life-threatening,”

No matter what becomes of this particular project, it seems that diamonds are becoming more precious to humanity than ever before.

More than Just Pennies from Heaven!

Following the last eruption of the volcano in Kamchatka, the world learned about previously unknown deposits of diamonds in an announcement made by the Russian Ministry of Education and Science. Stones found in and around the volcano proved to be so unique that Russian scientists have been forced to create new class of diamonds.

Near the end of 2012, the over 3000 meter high volcano erupted for the first time in 37 years in a fiery explosion ten times larger than the last. Every second, Kamchatka spewed 400 cubic meters of lava, with magma flows extending up to 10 km. This event not only forever changed the landscape of the peninsula, but also brought with it a gleam.

The unusual diamonds which were uncovered by the eruption are geologically different than those normally found in the region. This comes as a result of the high pressure and a crystallization of volcanic gases under the influence of electrical discharges and lightning. Though this is the first time that the process has been definitively identified in nature, the hypothesis that they could form in this was was posited by French scientists in 1964.

The diamonds discovered in Kamchatka resemble synthetic diamonds, and their structure is different from other known types of gemstones. Firstly, they did not originate in magma like other volcanic diamonds, and what is more is that the stones produced during the eruption are quite large, measuring between 25 and 70mm.

Only a small sample of lava managed to yield hundreds of diamonds, an impressive result when compared with the richest deposits in India (77 diamonds per pound) and Canada (1500 diamonds in a sample of 28 kg). It seems that there is more than a glimmer of opportunity in this new discovery!

Printing Fort Knox

According to industry experts, the future of 3D printers is largely dependent on their ability to print in metal. The latest reports from Research & Markets and IDTechEx show that metals are the fastest growing segment of 3D printing industry, with a 48% increase in sales of specialty printers and a 32% increase in sales of related components.

Being able to print in metal is the only chance for 3D printing to find viable application in mass production. Though plastic components have found numerous applications, ranging from the development of prototypes to education, only by forming metal can this technology accede to industrial production, and thus economic viability. Due to the prohibitive cost of the equipment, metal 3D printing was first adopted in the fields of biotechnology and aeronautics, which account for a 31% increase in worldwide demand for titanium.

More recently, this technology has been recognized by the goldsmithing industry, which has in turn led to the development of specialty printers designed to use precious metals. A handful of jewelers today are now able to meet even the most complex customer demands, and produce jewelry which would not have before been possible.

In the same vein, interest is also growing on the part of mints, which have already made the first attempts to print coins and bars. As a result, gold dust – the basic raw material for this type of printing – is today responsible for 49% of the market share of all metal 3D printer cartridges.

Plasmons and the ‘Gold Rainbow’

Anyone who has ever been in the market for jewelry knows the basic colors of gold – namely yellow, white and pink. The hue depends on the ratio of copper, silver, and platinum added to the mix – an art which can yield spectacular results. Bearing this in mind, you would think that lilac coloured gold seems impossible. Now, with the help of science, everything is possible – all you need is a solution of water and salt – and plasmons, of course!

The magic plasmons lies in the ‘plasma oscillation’ of which it is a base. Plasma oscillation arises from an instability in the free electron gas density, distorting the way in which we perceive the visual properties of the metal. This is because it directly affects the wavelengths of light absorbed and refracted by the metal. Thanks to this extraordinary property, we can easily affect the colour of gold. This has long been applied in the production of stained glass (particularly the deep reds common in church windows), but is now seeing a rising popularity in the manufacturing of jewelry.

While red seems to be the easiest colour to obtain, with the right tweaking, cooler colours (including blue) are attainable. It all depends on the size of the gold nanoparticles present in the mixture. Their size dictates the change in colour – from hot red to deep purple, from a pleasing lilac to a deep blue. As fascinating as this is, you are probably wondering how it is possible that we can manipulate this phenomenon.

Firstly, we must understand that the natural charge of gold particles causes them to repel each other, keeping them ‘small’ – this yields the yellow colour that is most commonly associated with the metal. By adding salt, one can affect the relationship between particles and cause them to clump, thus changing not only their ‘size,’ but also the effect of the plasmons on how we perceive their colour.

With gold finding more and more applications, new technology and scientific research are constantly increasing the range of possibilities that it presents. Who is to say what the future might bring for the ‘gold rainbow’?

New Zealand’s Liquid Gold

According to the latest research published in the journal Geothermics, the area around New Zealand’s Taupo volcano possesses huge reserves of precious metals. Although the presence of gold in this volcanic area is not a new phenomenon, it does have a most unusual form.

The main author of the study, Stuart Simmons of the University of Utah, reminds us that the presence of gold and silver in the hot springs is nothing new. Such ores were first discovered more than half a century ago in New Zealand’s “Champagne Pool” (picture below), one of the few places in the world where tourists can actually observe the aforementionned process. The deposits of precious metals, together with mercury and arsenic, create a distinctive orange hue at the edges of the spring.

Extremely hot magma heats the water stored in underground reservoirs which, thanks to a specific chemical composition, errodes the surrounding rock. This in turn allows particles of gold and silver to break free and fall freely to the bottom of the solution. If an effective way to harness this process in a mining context could be found, the resulting metals extracted could be valued at as much as $2.7 million.

The road to unlocking the secrets of the pools on the northern island of New Zealand was a long one. A decade and a half ago, Simmons’ team built a special device that was lowered nearly 2 km below the surface. In this way, a ‘hot sample’ was obtained, and after 5 years, researchers have been able to derrive preliminary estimates for the quantities of precious metals present in the mix.

These long years of research have paid off, as their research has highlighted as many as 18 resevoirs containing tens of thousands of ounces of gold, and hundreds of thousands (if not more) ounces of silver. We are now left with only one problem – how to get at this incredible deposit. Equipment used in the extraction of ore would have to withstand extreme conditions, including water as hot as 400 degrees.

As for a finder’s fee, investigators have not yet made a penny from their discovery. It would seem that for now, all this hard work has been in the name of science.

MW