Diamonds are forever – whether made in a lab or mined from the earth

Are you in the market for some sparkle?
clearviewstock/Shutterstock.com

Joshua Wilhide, University of Maryland, Baltimore County and William LaCourse, University of Maryland, Baltimore County

It's diamond season. Almost 40 percent of American engagements happen between Thanksgiving and Valentine's Day, with Christmas the most popular day to pop the question – and hand over a sparkly piece of ice. Jewelry stores do at least double their usual monthly sales in December.

Since at least the late 1800s, with the discovery of huge diamond mines in South Africa, people have treasured these dazzling gems. The beauty and splendor of diamonds goes well beyond the surface. Like a diamond hunter digging in an underground mine, one must look deeper to their atomic characteristics to understand what sets these stones apart – and what makes them valuable not just for romantics but also for scientists.

On the atomic level

A literal diamond in the rough, before it's been removed from the matrix within which it formed.
USGS, CC BY

When mined from the earth, diamonds look like cloudy rocks before they're cut and polished. Their chemical nature and structure were unknown for centuries. It was Isaac Newton's experiments in the 1600s that first suggested diamonds are made up of the fourth-most abundant element, carbon.

People doubted Newton's discovery, which is understandable considering how different diamonds look from other common forms of carbon, like the graphite in pencils or the ash left over in a wood-burning fireplace. But in 1797, English scientist Smithson Tennant confirmed the composition of diamonds.

Diamond and graphite are both made of carbon atoms, but organized in different structures.
Materialscientist/Wikimedia Commons, CC BY-SA

It turns out that carbon takes two common forms that have crystalline structures on the atomic level. Graphite is a repeating two-dimensional, honeycomb-like shape, with layers stacking on top of each other. Alternatively, carbon can form a repeating three-dimensional shape, a tetrahedron – and that's your diamond.

Where do they come from?

There are two sources of the precious gemstone: natural mining or synthesis within a laboratory.

Natural diamonds are formed under intense pressure and heat in the Earth's crust over millions of years. Natural deposits have been found all over the world, from Northern Canada to Western Australia, even underwater in Namibia.

Mines were the only source of the gemstone until 1955, when General Electric produced the first synthetic diamond using what's called the high-pressure, high-temperature process. This process works by applying hundreds of thousands pounds of pressure to graphite at 2,700 degrees Fahrenheit to force the carbon into the correct crystalline structure. It's sort of like an artificial version of the extreme conditions that produce diamonds deep within the earth.

In the 1970s, labs started to use the chemical vapor deposition method to grow diamonds at lower pressures. At the time, the HPHT technique couldn't produce a gem-quality stone. This improved method converts a hydrocarbon gas mixture by breaking it down to its components, carbon and hydrogen molecules, with an intense heated filament or plasma and deposits it onto a substrate, ultimately forming a solid diamond. Originally, this process had a very slow growth rate, but it's now optimized to grow quality diamonds within days.

Together these techniques are largely responsible for human-made diamonds – upwards of 4 billion carats worldwide annually.

There's a common misconception that a natural diamond must be inherently different than a synthetic diamond. To the contrary, they are chemically identical and share the same physical properties. Even the most sophisticated techniques can not detect a difference between a flawless mined diamond and a flawless human-made diamond – both are "real" diamonds. However, truly flawless diamonds of either type are extremely scarce.

Assessing a diamond

No matter its origin, a diamond can be assessed by the "four Cs" of cut, color, clarity and carat weight. Specialized laboratories grade each category, as created by the Gemological Institute of America.

Diamond cutters choose the shape of the finished stone.
SPbPhoto/Shutterstock.com

The cut of a diamond is defined in two ways. There's "the general shape of the cut stone," with shapes including round brilliant (most common), oval, emerald, pear, princess, trilliant, triangle, heart and radiant. And there's "the degree of perfection achieved by the cutting and polishing process" as rated on a scale ranging from excellent to poor. The type and quality of the cut ultimately determines the way light reflects in the stone, contributing to its "brilliance."

The color of a diamond is graded on a scale from "D," being perfectly colorless, to "Z" having the most color. Originally, the color of the stone was a huge hint about how it was formed because until 2007 about 90 percent of the high-pressure, high-temperature synthetic stones were yellow orange or yellow. Almost no stones from that process were colorless, so a colorless stone was almost certainly natural. But the HPHT growing process has greatly improved and as of 2016, 43 percent of synthetic diamonds were colorless.

Diamond clarity indicates the presence of inclusions, or tiny imperfections, in the stone. Inclusions make every diamond unique and provide strong clues to whether a diamond is natural or synthetic. The HPHT process uses metal flux, or a hot metal liquid, which acts as a solvent to dissolve the carbon source, graphite, to be rearranged and grown into a diamond. Diamonds grown this way can have inclusions of metals. The resulting stones may be magnetic – if a diamond reacts with a magnet, it is certainly synthetic. Additionally, most synthetic diamonds receive high clarity grades, while natural diamonds contain larger inclusions.

Many consumers focus on carat weight – that is, diamond size. The stone is weighed on a scale where one carat is 200 milligrams (0.007 ounces). Diamonds larger than four carats are almost guaranteed to be natural because that's the limit for the size of the diamonds that the synthetic processes can grow.

Although the "four Cs" of diamonds ultimately define retail value, sentimental value can be even greater. Buyers must decide if a natural or synthetic stone fits the bill for them, based on factors that might include the ecological and ethical ramifications of diamond mining as well as the lower price tag for synthetic rocks.

Diamonds found beyond your ring finger

Although diamonds are well known for their place in the jewelry industry, they play other valuable roles, too.

Their physical properties, especially hardness, are ideal for abrasive applications. Small diamonds can be found coating cutting wheels, drill bits and grinding wheels, which are used for cutting concrete or brickwork.

Diamonds also have certain optical properties that make them suitable for various spectroscopy techniques, or measurements involving the electromagnetic spectrum. Scientific researchers use these tests to help identify the composition of materials they're investigating.

A diamond needle is what's in contact with the grooves on a record.
Michelle Hawkins-Thiel/Flickr, CC BY

A previously common place for diamonds was on record players, where to this day the needle that touches the record can be a very small diamond sliver.

Whether one appreciates the aesthetic or scientific characteristics of the gem more, diamonds can dazzle.

Joshua Wilhide, Manager of the Molecular Characterization and Analysis Complex, University of Maryland, Baltimore County and William LaCourse, Professor of Chemistry and Dean of the College of Natural and Mathematical Sciences, University of Maryland, Baltimore County

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Diamonds are forever – whether made in a lab or mined from the earth

Are you in the market for some sparkle?
clearviewstock/Shutterstock.com

Joshua Wilhide, University of Maryland, Baltimore County and William LaCourse, University of Maryland, Baltimore County

It's diamond season. Almost 40 percent of American engagements happen between Thanksgiving and Valentine's Day, with Christmas the most popular day to pop the question – and hand over a sparkly piece of ice. Jewelry stores do at least double their usual monthly sales in December.

Since at least the late 1800s, with the discovery of huge diamond mines in South Africa, people have treasured these dazzling gems. The beauty and splendor of diamonds goes well beyond the surface. Like a diamond hunter digging in an underground mine, one must look deeper to their atomic characteristics to understand what sets these stones apart – and what makes them valuable not just for romantics but also for scientists.

On the atomic level

A literal diamond in the rough, before it's been removed from the matrix within which it formed.
USGS, CC BY

When mined from the earth, diamonds look like cloudy rocks before they're cut and polished. Their chemical nature and structure were unknown for centuries. It was Isaac Newton's experiments in the 1600s that first suggested diamonds are made up of the fourth-most abundant element, carbon.

People doubted Newton's discovery, which is understandable considering how different diamonds look from other common forms of carbon, like the graphite in pencils or the ash left over in a wood-burning fireplace. But in 1797, English scientist Smithson Tennant confirmed the composition of diamonds.

Diamond and graphite are both made of carbon atoms, but organized in different structures.
Materialscientist/Wikimedia Commons, CC BY-SA

It turns out that carbon takes two common forms that have crystalline structures on the atomic level. Graphite is a repeating two-dimensional, honeycomb-like shape, with layers stacking on top of each other. Alternatively, carbon can form a repeating three-dimensional shape, a tetrahedron – and that's your diamond.

Where do they come from?

There are two sources of the precious gemstone: natural mining or synthesis within a laboratory.

Natural diamonds are formed under intense pressure and heat in the Earth's crust over millions of years. Natural deposits have been found all over the world, from Northern Canada to Western Australia, even underwater in Namibia.

Mines were the only source of the gemstone until 1955, when General Electric produced the first synthetic diamond using what's called the high-pressure, high-temperature process. This process works by applying hundreds of thousands pounds of pressure to graphite at 2,700 degrees Fahrenheit to force the carbon into the correct crystalline structure. It's sort of like an artificial version of the extreme conditions that produce diamonds deep within the earth.

In the 1970s, labs started to use the chemical vapor deposition method to grow diamonds at lower pressures. At the time, the HPHT technique couldn't produce a gem-quality stone. This improved method converts a hydrocarbon gas mixture by breaking it down to its components, carbon and hydrogen molecules, with an intense heated filament or plasma and deposits it onto a substrate, ultimately forming a solid diamond. Originally, this process had a very slow growth rate, but it's now optimized to grow quality diamonds within days.

Together these techniques are largely responsible for human-made diamonds – upwards of 4 billion carats worldwide annually.

There's a common misconception that a natural diamond must be inherently different than a synthetic diamond. To the contrary, they are chemically identical and share the same physical properties. Even the most sophisticated techniques can not detect a difference between a flawless mined diamond and a flawless human-made diamond – both are "real" diamonds. However, truly flawless diamonds of either type are extremely scarce.

Assessing a diamond

No matter its origin, a diamond can be assessed by the "four Cs" of cut, color, clarity and carat weight. Specialized laboratories grade each category, as created by the Gemological Institute of America.

Diamond cutters choose the shape of the finished stone.
SPbPhoto/Shutterstock.com

The cut of a diamond is defined in two ways. There's "the general shape of the cut stone," with shapes including round brilliant (most common), oval, emerald, pear, princess, trilliant, triangle, heart and radiant. And there's "the degree of perfection achieved by the cutting and polishing process" as rated on a scale ranging from excellent to poor. The type and quality of the cut ultimately determines the way light reflects in the stone, contributing to its "brilliance."

The color of a diamond is graded on a scale from "D," being perfectly colorless, to "Z" having the most color. Originally, the color of the stone was a huge hint about how it was formed because until 2007 about 90 percent of the high-pressure, high-temperature synthetic stones were yellow orange or yellow. Almost no stones from that process were colorless, so a colorless stone was almost certainly natural. But the HPHT growing process has greatly improved and as of 2016, 43 percent of synthetic diamonds were colorless.

Diamond clarity indicates the presence of inclusions, or tiny imperfections, in the stone. Inclusions make every diamond unique and provide strong clues to whether a diamond is natural or synthetic. The HPHT process uses metal flux, or a hot metal liquid, which acts as a solvent to dissolve the carbon source, graphite, to be rearranged and grown into a diamond. Diamonds grown this way can have inclusions of metals. The resulting stones may be magnetic – if a diamond reacts with a magnet, it is certainly synthetic. Additionally, most synthetic diamonds receive high clarity grades, while natural diamonds contain larger inclusions.

Many consumers focus on carat weight – that is, diamond size. The stone is weighed on a scale where one carat is 200 milligrams (0.007 ounces). Diamonds larger than four carats are almost guaranteed to be natural because that's the limit for the size of the diamonds that the synthetic processes can grow.

Although the "four Cs" of diamonds ultimately define retail value, sentimental value can be even greater. Buyers must decide if a natural or synthetic stone fits the bill for them, based on factors that might include the ecological and ethical ramifications of diamond mining as well as the lower price tag for synthetic rocks.

Diamonds found beyond your ring finger

Although diamonds are well known for their place in the jewelry industry, they play other valuable roles, too.

Their physical properties, especially hardness, are ideal for abrasive applications. Small diamonds can be found coating cutting wheels, drill bits and grinding wheels, which are used for cutting concrete or brickwork.

Diamonds also have certain optical properties that make them suitable for various spectroscopy techniques, or measurements involving the electromagnetic spectrum. Scientific researchers use these tests to help identify the composition of materials they're investigating.

A diamond needle is what's in contact with the grooves on a record.
Michelle Hawkins-Thiel/Flickr, CC BY

A previously common place for diamonds was on record players, where to this day the needle that touches the record can be a very small diamond sliver.

Whether one appreciates the aesthetic or scientific characteristics of the gem more, diamonds can dazzle.

Joshua Wilhide, Manager of the Molecular Characterization and Analysis Complex, University of Maryland, Baltimore County and William LaCourse, Professor of Chemistry and Dean of the College of Natural and Mathematical Sciences, University of Maryland, Baltimore County

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Small moments, big news: The Indy's best of 2018

Dear Readers,

So much of the story of Colorado happens in smaller moments in people's lives. As 2018 winds down, we look back over our year covering these moments and the larger issues they revealed about our state.

A mother in the immigrant detention facility in Aurora couldn't eat or sleep because her son was yanked from her at the border and she didn't know where he was.

A sick, elderly woman sat at her kitchen table in rural Colorado describing the helplessness of having to rely on a public transit system with service so limited that she has to wait a week for a ride.

State inmates ate breakfast in the predawn darkness of a forest before heading out for another day of fighting fires. The job pays them next to nothing, but, they said, it makes them feel valued.

Democratic governor-elect Jared Polis speaks at his midterm election night party in Denver on Nov. 6, 2018. (Photo by Evan Semón)

Because this was an election year, much of our coverage was aimed at educating voters - from columnist Mike Littwin's weekly gubernatorial rankings and behind-the-scenes look at that race to our in-depth explainers of ballot issues, which hundreds of thousands of Coloradans relied on to fill out their ballots. Those explainers dominated our most-read lists of this year, but it was our in-depth profiles of Jared Polis and Walker Stapleton that stood out as examples of The Indy at its best. Alex Burness's four-part portrait, "How Jared Polis Gets What He Wants," is still the most thorough look at the background and business and political lives of the man who will become governor on Jan. 8.

Sen. Randy Baumgardner, a Hot Sulphur Springs Republican, on the Senate floor on March 26, 2018. (Photo by John Herrick)

The 2018 state legislative session was marked by #MeToo turmoil. Some of the best work on our team came from John Herrick and Littwin. We were especially keen on the above photo John took of Republican Randy Baumgardner, the oft-accused sexual harasser who resigned from the state Senate earlier this month to avoid expulsion in January. The picture at once captures Baumgardner's swagger and defiance, the exhausting tension of this year's session, and the isolation borne from accusations of workplace lechery in the #MeToo era. It's one of those small moments that we at The Indy are big on capturing.

Russian thistle in a former reservoir along the Colorado River in Hite, Utah, in October 2018. (Photo by John Herrick)

On the environmental beat, we took a hard look at why, three years after Gov. John Hickenlooper released Colorado's first statewide water plan, the strategy to avoid a looming water shortfall still has scant funding. Water policy can be - pardon the pun - one of the driest topics out there, but with our climate changing and Colorado now 19 years into a record-long drought, this juicy story by Editor Susan Greene is worth your time. Watch in 2019 for how, if at all, the new administration and legislature make progress averting a water crisis.

Susan was the first to report that six former Anadarko employees came forward on behalf of investors to describe a culture of corporate callousness that puts profits before safety. The six include the oil and gas giant's one-time chief lobbyist and spokeswoman, both of whom say Anadarko can't be trusted to maintain deteriorating wells like the one that caused the 2016 fatal home explosion in Firestone. We were struck by former Anadarko spokeswoman Robin Olsen's assertion that her boss told her to "keep quiet" about the safety concerns and that her job "was to shovel shit, and to clean up the messes" the company's employees made.

Two women protest at the ICE detention facility in Aurora on Aug. 2, 2018. (Photo by Alex Burness)

When news spread over the summer that the federal government was separating immigrant families at the border, it instantly became the biggest story in the nation. Alex broke the news that dozens of parents who had been separated from their children at the border were being held at the ICE detention center in Aurora and published accounts of their ordeals. "He kept asking for me and telling me that he didn't want me to be (away from him). I said I love him a lot. We were both crying," one mother said of the moment officers took her 6-year-old son from her.

Bryan Saenz, a work-study student at Community College of Denver, organizes food in the school's food pantry on Nov. 14, 2018. (Photo by Rachel Lorenz for The Colorado Independent)

We've all heard that students who skip meals or don't eat enough are more likely to have lower grade point averages than other kids. But we didn't know the extent to which many college students in Colorado are going hungry. We explored the emerging trend of on-campus food pantries, which serve student populations increasingly suffering from hunger as rent and tuition costs skyrocket. Rachel Lorenz and Forest Wilson, both students themselves, had the story.

Earlier this month, intern rockstar Shannon Mullane took a sobering look at the growing problem of suicide in rural Colorado, including how kids are especially vulnerable. These were tough stories, but the talent and commitment of young journalists like Shannon, Rachel and Forest gives us hope for the future of our craft in Colorado.

Clarence Moses-EL speaks to a gaggle or reporters after a jury found him not guilty of assault on Nov. 12, 2016. Moses-EL spent 28 years in prison on the wrongful conviction. (Photo by Susan Greene)

The Indy continues to lead in covering criminal justice. We broke news that Denver District Attorney Beth McCann has blocked state compensation for a wrongfully convicted man whose mistreatment she highlighted as a campaign issue. We were the only outlet to cover efforts by the Douglas County Sheriff's Department to pin a break-in and sexual assault on a cognitively delayed teenager from whom its detectives coerced a confession. And we were the first to report that an investigator for death row inmate Robert Ray chose jail time rather than testify as a prosecution witness.

In that same capital case, we took a close look at remarks by the jury foreman who wrote that what he knows about African-Americans is "bad news." There was a moment in the courthouse elevator when, clearly shaken by questions about his racial views, juror Carl Dubler said he wouldn't discuss them with the news media. But the white software marketer from Centennial opened up to Susan a few weeks later about the weight of having sentenced a young African-American man to death. "Now I can see how dangerous the whole job of judgment is," he told her.

Rep. Faith Winter, D-Westminster, embraces Dafna Michaelson Jenet, D-Commerce City, ahead of a historic vote to expel Rep. Steve Lebsock from office, who Winter accused of sexual harassment, on March 2, 2018. (Photo by John Herrick)

In yet another year without a haircut, Littwin was busy capturing moments like Walker Stapleton's outburst at a gubernatorial debate: "He's mad - red-faced mad, sweaty-brow mad, yelling-into-the-mic mad - because Coloradans seem not to understand how dangerous the 'radical and extreme' Polis would be as governor." And of the moment state Rep. Steve Lebsock, accused of sexual harassment at the statehouse, switched party affiliations, from Democrat to Republican, in order to stick it to the party that wanted him gone, Littwin wrote: "It was one of the finest days ever witnessed at the state legislature. It was so moving, so emotional, so powerful that only a self-righteous, self-absorbed vindictive jerk like Steve Lebsock could have ruined it. And so he did. Or tried to, anyway." Upon learning that his friend, Rob Hiaasen, and Hiaasen's colleagues were killed by a shooter in their Capital Gazette newsroom in Annapolis, Md., Littwin said: "I mourn for a friend, I mourn for my business. And, as all of us do, I mourn knowing there will inevitably be more tears, after more shootings, after more deaths, in what has become an endlessly tragic news cycle that America has steadfastly refused to address."

By Mike Keefe

This mass shooting habit inevitably prods Pulitzer-winning editorial cartoonist Mike Keefe to pick up his pens. But there were plenty of other outrages to 'toon about this year, including the assassination of Saudi journalist Jamal Khashoggi, Trump's complicity in the matter, the Brett Kavanaugh nomination to the Supreme Court and the Senate's handling of accuser Christine Blasey Ford. Keefe also got spun up about climate change, propaganda about climate change, propaganda in general, and flat-out lies.

The Colorado Independent's editor, Susan Greene, was handcuffed and detained by Denver police officers on Colfax Avenue on July 5. (Screenshot via body-cam footage provided by city of Denver)

This was the year in which The Indy's ongoing fight for a transparent and accountable government took a more personal turn. Denver police handcuffed and detained Susan as she was taking photos of a police scene on a public sidewalk. You may remember the moment, caught by body cam, when officers ordered Susan to "act like a lady," or her musing in her column about "how exactly a woman should behave on a perp walk after having been blocked from doing her job, obstructed from exercising her First Amendment rights, handcuffed and otherwise manhandled by an ignorant and over-amped police officer and his sidekick." Almost six months later, Denver police still haven't released their investigation of the 14-minute incident.

A copy of The Colorado Independent's petition before the U.S. Supreme Court

We in our small but mighty nonprofit newsroom are proud to have stood up against a dangerous legal precedent - the sealing of key court documents in one of Colorado's three death-row cases - by petitioning the U.S. Supreme Court to hear the case of The Colorado Independent v. District Court for the Eighteenth Judicial District of Colorado. We're also proud that we're backed in that effort by the Colorado Press Association and all of Colorado's top news outlets as well as most of the leading news organizations in the United States. We've built a national coalition of news outlets and First Amendment scholars joined in solidarity against case law that threatens to erode our ability to do our most basic job: watchdogging government. It is not just our responsibility to report news, but also to champion and defend all Americans' right to scrutinize powerful institutions. Check out Susan's piece explaining why we've taken on this fight.

The Indy has a mission. It's there on our home page for all to read. "The Colorado Independent's award-winning team of investigative and explanatory reporters and news commentators aims to hold public officials to account, shine light on the relationships between people, power and policy, and amplify the voices of Coloradans whose stories are unheard." Looking back on our coverage this year, we're pleased to have stayed true to these goals.

We're honored to be able to do this work in this interesting time, yet especially tough spell for our industry. We're grateful for the skyrocketing number of Coloradans who are reading The Indy, and to those among you who've supported our nonprofit newsroom. If you've given, thank you! If you've not yet backed our work, please make a tax-deductible contribution now. The deadline for the 2018 tax year is midnight tonight. We need your help. You need smart, in-depth, public-interest news. And Colorado needs veteran journalists reporting on moments that matter in this state and, when necessary, who are willing to speak truth to power.

We wish you a happy, healthy 2019.

The Colorado Independent team (Photo by Evan Semon)

The Colorado Independent team

The post Small moments, big news: The Indy's best of 2018 appeared first on The Colorado Independent.

Diamonds are forever – whether made in a lab or mined from the earth

Are you in the market for some sparkle?
clearviewstock/Shutterstock.com

Joshua Wilhide, University of Maryland, Baltimore County and William LaCourse, University of Maryland, Baltimore County

It's diamond season. Almost 40 percent of American engagements happen between Thanksgiving and Valentine's Day, with Christmas the most popular day to pop the question – and hand over a sparkly piece of ice. Jewelry stores do at least double their usual monthly sales in December.

Since at least the late 1800s, with the discovery of huge diamond mines in South Africa, people have treasured these dazzling gems. The beauty and splendor of diamonds goes well beyond the surface. Like a diamond hunter digging in an underground mine, one must look deeper to their atomic characteristics to understand what sets these stones apart – and what makes them valuable not just for romantics but also for scientists.

On the atomic level

A literal diamond in the rough, before it's been removed from the matrix within which it formed.
USGS, CC BY

When mined from the earth, diamonds look like cloudy rocks before they're cut and polished. Their chemical nature and structure were unknown for centuries. It was Isaac Newton's experiments in the 1600s that first suggested diamonds are made up of the fourth-most abundant element, carbon.

People doubted Newton's discovery, which is understandable considering how different diamonds look from other common forms of carbon, like the graphite in pencils or the ash left over in a wood-burning fireplace. But in 1797, English scientist Smithson Tennant confirmed the composition of diamonds.

Diamond and graphite are both made of carbon atoms, but organized in different structures.
Materialscientist/Wikimedia Commons, CC BY-SA

It turns out that carbon takes two common forms that have crystalline structures on the atomic level. Graphite is a repeating two-dimensional, honeycomb-like shape, with layers stacking on top of each other. Alternatively, carbon can form a repeating three-dimensional shape, a tetrahedron – and that's your diamond.

Where do they come from?

There are two sources of the precious gemstone: natural mining or synthesis within a laboratory.

Natural diamonds are formed under intense pressure and heat in the Earth's crust over millions of years. Natural deposits have been found all over the world, from Northern Canada to Western Australia, even underwater in Namibia.

Mines were the only source of the gemstone until 1955, when General Electric produced the first synthetic diamond using what's called the high-pressure, high-temperature process. This process works by applying hundreds of thousands pounds of pressure to graphite at 2,700 degrees Fahrenheit to force the carbon into the correct crystalline structure. It's sort of like an artificial version of the extreme conditions that produce diamonds deep within the earth.

In the 1970s, labs started to use the chemical vapor deposition method to grow diamonds at lower pressures. At the time, the HPHT technique couldn't produce a gem-quality stone. This improved method converts a hydrocarbon gas mixture by breaking it down to its components, carbon and hydrogen molecules, with an intense heated filament or plasma and deposits it onto a substrate, ultimately forming a solid diamond. Originally, this process had a very slow growth rate, but it's now optimized to grow quality diamonds within days.

Together these techniques are largely responsible for human-made diamonds – upwards of 4 billion carats worldwide annually.

There's a common misconception that a natural diamond must be inherently different than a synthetic diamond. To the contrary, they are chemically identical and share the same physical properties. Even the most sophisticated techniques can not detect a difference between a flawless mined diamond and a flawless human-made diamond – both are "real" diamonds. However, truly flawless diamonds of either type are extremely scarce.

Assessing a diamond

No matter its origin, a diamond can be assessed by the "four Cs" of cut, color, clarity and carat weight. Specialized laboratories grade each category, as created by the Gemological Institute of America.

Diamond cutters choose the shape of the finished stone.
SPbPhoto/Shutterstock.com

The cut of a diamond is defined in two ways. There's "the general shape of the cut stone," with shapes including round brilliant (most common), oval, emerald, pear, princess, trilliant, triangle, heart and radiant. And there's "the degree of perfection achieved by the cutting and polishing process" as rated on a scale ranging from excellent to poor. The type and quality of the cut ultimately determines the way light reflects in the stone, contributing to its "brilliance."

The color of a diamond is graded on a scale from "D," being perfectly colorless, to "Z" having the most color. Originally, the color of the stone was a huge hint about how it was formed because until 2007 about 90 percent of the high-pressure, high-temperature synthetic stones were yellow orange or yellow. Almost no stones from that process were colorless, so a colorless stone was almost certainly natural. But the HPHT growing process has greatly improved and as of 2016, 43 percent of synthetic diamonds were colorless.

Diamond clarity indicates the presence of inclusions, or tiny imperfections, in the stone. Inclusions make every diamond unique and provide strong clues to whether a diamond is natural or synthetic. The HPHT process uses metal flux, or a hot metal liquid, which acts as a solvent to dissolve the carbon source, graphite, to be rearranged and grown into a diamond. Diamonds grown this way can have inclusions of metals. The resulting stones may be magnetic – if a diamond reacts with a magnet, it is certainly synthetic. Additionally, most synthetic diamonds receive high clarity grades, while natural diamonds contain larger inclusions.

Many consumers focus on carat weight – that is, diamond size. The stone is weighed on a scale where one carat is 200 milligrams (0.007 ounces). Diamonds larger than four carats are almost guaranteed to be natural because that's the limit for the size of the diamonds that the synthetic processes can grow.

Although the "four Cs" of diamonds ultimately define retail value, sentimental value can be even greater. Buyers must decide if a natural or synthetic stone fits the bill for them, based on factors that might include the ecological and ethical ramifications of diamond mining as well as the lower price tag for synthetic rocks.

Diamonds found beyond your ring finger

Although diamonds are well known for their place in the jewelry industry, they play other valuable roles, too.

Their physical properties, especially hardness, are ideal for abrasive applications. Small diamonds can be found coating cutting wheels, drill bits and grinding wheels, which are used for cutting concrete or brickwork.

Diamonds also have certain optical properties that make them suitable for various spectroscopy techniques, or measurements involving the electromagnetic spectrum. Scientific researchers use these tests to help identify the composition of materials they're investigating.

A diamond needle is what's in contact with the grooves on a record.
Michelle Hawkins-Thiel/Flickr, CC BY

A previously common place for diamonds was on record players, where to this day the needle that touches the record can be a very small diamond sliver.

Whether one appreciates the aesthetic or scientific characteristics of the gem more, diamonds can dazzle.

Joshua Wilhide, Manager of the Molecular Characterization and Analysis Complex, University of Maryland, Baltimore County and William LaCourse, Professor of Chemistry and Dean of the College of Natural and Mathematical Sciences, University of Maryland, Baltimore County

This article is republished from The Conversation under a Creative Commons license. Read the original article.