by Andrew W. Fox and Claudia Copeland, PhD
What is a diamond? On the surface, the answer is simple– essentially, a diamond is just carbon. The same element that is found in the large molecules that make up a slice of bread, tree trunks, and our own bodies. Pure carbon can also be found as graphite—pencil “lead”. But while both diamond and graphite are pure carbon, the carbon of a real diamond is clearly not the same as graphite—the beauty of these sparkling, clear stones makes that obvious. Less obvious is the difference between mined diamonds and lab-grown diamonds, which have essentially the same chemical structure, but are worlds apart in economic and intangible value. To appreciate how intrinsically different a mined diamond is from a lab-grown diamond, it’s first necessary to understand the incredible story of how carbon deep in the earth forms into the beautiful diamonds we can mine, cut, and fashion into exquisite jewelry.
The structure of a diamond
Diamonds are a stone of purity. Containing just a single type of atom—carbon—their beauty lies in their perfect crystal structure, known as a diamond lattice. Whereas graphite, the other form of pure carbon, is structured in flat layers of carbon molecules that can easily slide off of each other, diamond has an extremely strong 3-dimensional structure. This is what’s responsible for its top-of-the-list position among gemstones for hardness. In order to produce this structure, some very special conditions need to take place.
How diamonds are made: heat, pressure, and high-speed transportation
The natural state for a group of lazy carbon atoms is graphite, not diamond. In order to push those atoms into forming a diamond lattice, you need conditions of extremely high heat and pressure. Specifically, the temperature needs to be 900 – 1300 °C and the pressure needs to be 45-60 kB. That’s really hot, and under pressure that’s roughly 50,000 times stronger than what we feel at the earth’s surface! On Earth, these conditions can only be found deep below the earth’s crust—about 100 miles below the surface, in the layer where minerals bend and compress like plastic—the mantle.
This layer is far too deep for even the most advanced drills to reach, so the diamonds found in mines had to first form in the mantle and then rise up into the topmost solid layer of the earth. There’s one problem with this, though— while the extremely hot and high-pressure conditions of the mantle favor formation of the diamond lattice, the conditions of the crust (what we could consider “ordinary conditions on earth”) favor the formation of graphite. So, diamonds that rise slowly from the mantle into the crust will simply turn into graphite.
Now, if carbon is already in the diamond formation under normal crust conditions, it will retain its diamond structure, even though the carbons “want” to be graphite under surface temperature and pressure. This is because the energy required for the transformation from diamond to graphite at the surface is prohibitively high—no matter how much the carbon atoms “want” to exist as graphite, they won’t transform because the energy needed to undergo the transition is far too high at the surface of the earth. But this transition energy is much lower deep in the earth, so if the diamond moves slowly up from the mantle, it will transform into graphite by the time it reaches the upper crust.
The only way to avoid this is to have the diamonds rise to the surface extremely rapidly—so fast that they don’t have time to convert from a diamond lattice into graphite. There’s only one high-speed transport available from the mantle to the crust of the earth: volcanoes. During volcanic eruptions, liquified rock (magma) rapidly rises to the surface. If it’s carrying carbon in the diamond lattice structure, these pockets of diamond lattice will not melt, and they won’t have time to transform into graphite. Instead, they will become frozen as diamonds embedded in the volcanic rock when it cools. The two major types of diamond-rich volcanic rock are kimberlite and lamproite, and these volcanic rocks are much younger than the diamonds they transport—essentially, these rocks at the time of eruption were just molten conveyor belts, transporting diamonds to the surface that were already old. In fact, many diamonds are over 3 billion years old— and all diamonds are at least 990,000,000 years old!
The Rarity of Natural Diamonds
Because diamonds can only come to us through these specific conditions of heat, pressure, and rapid transit, they are only present in the crust of the earth in a few select places—specifically, in areas with “kimberlite pipes”—deep shafts of volcanic stone that formed as molten rock during a volcanic eruption. These pipes contain diamonds embedded in the volcanic rock where they were frozen in place as the molten, liquid magma cooled into solid rock within the earth’s crust.
Diamond-containing pipes aren’t everywhere—they are only found in certain locations, and most often are located far from the people who most want them. Although the discovery of diamonds in South Africa in the 19th Century substantially increased the number of diamonds worldwide, natural diamonds remain a rare and valuable type of gemstone. While diamonds were initially discovered in South Africa in rivers that had washed them down from kimberlite deposits, for the most part, diamonds must be mined from the volcanic pipes themselves. (This process may become easier, however, at least in West Africa, where plants that grow above kimberlite pipes have been discovered. If kimberlite-loving plants could be found in other regions, this could substantially reduce the environmental impact of searching for diamond deposits by strip mining.)
The Intrinsic Value of Natural Diamonds
Because of their rarity, natural diamonds have an intrinsic value that goes far beyond their sparkle. You cannot make something that is more than 900 million years old; a stone that has been formed deep in the earth and brought to us by magma in volcanic pipes is something genuinely special. The geological forces required to make a natural diamond make them truly worthy of reverence.
Of course, the ingenuity that has gone into figuring out how to make diamonds in a lab is also something special. Lab-grown diamonds have the same physical properties as natural mined diamonds, so they are a great resource for industrial processes that need a substance with the hardness of a diamond but for an affordable price. However, the intrinsic value of a lab-grown diamond gem is limited to its beauty and the admiration for the scientists who have figured out how to make these stones, as opposed to the awe-inspiring geological history behind every natural diamond.
The Economics of Natural vs. Lab-Grown Diamonds
Besides the geological wonder of their creation, natural diamonds also have a higher economic value. Because natural diamonds can only be mined, and can only be mined from certain limited geographic locations, their supply is limited. Not so with lab-grown diamonds.
While it is true that lab-grown diamonds are real diamonds, they have a different crystal structure that is readily visible under a microscope. So, while a lab-grown diamond is a type of diamond, it is not the same as a natural diamond. In economic terms, lab-grown diamonds can continue to be produced in as large a supply as the market is willing to bear. And, like most technologies, the cost of producing them will come down steadily as the technology used to make them becomes more efficient. So, while you may pay 30-40% less for a lab-grown diamond vs. a natural diamond, what you do pay will essentially be lost as the lab-grown diamond has little resale value. While diamond traders buy and sell mined diamonds, most traders will not buy lab-grown diamonds, according to diamond trader Alan Bronstein. The reason is the lack of any cap on supply. Buying a lab-grown diamond is essentially like buying an expensive cell phone—if you love it, you should certainly buy it and enjoy its sleek beauty. But it is not something that will hold its value over time.
But What if I Can’t Afford a Mined Diamond?
Of course, price is a reality. You may simply not have the money for a natural mined diamond. If this is the case, suggests diamond industry consultant Tom Gelb, it would be better to stick with a lower-price diamond substitute. According to Mr. Gelb, you can buy a lab-grown cubic zirconia that is the same size as a $3,500 lab-grown diamond for about $25, or a created moissanite which has excellent light reflection properties, ie: moissanite is very fiery. Since neither stone has any substantial resale value, his assessment is that it makes more sense to buy a diamond substitute rather than a synthetic diamond.
Another alternative, if you cannot afford a natural mined diamond, is to buy another natural mined stone. Both white sapphires—which are almost as hard as diamonds—and white zircons are natural, clear stones that have a true geological history. Zircons, in fact, are the oldest mineral on earth, lending them plenty of geological authenticity, and they display brilliance and fire approaching that of diamonds. In addition, they are interesting: because they are so old, they can be used to study events that happened hundreds of millions of years ago. While these stones are not as valuable as diamonds, they will hold their value because, unlike lab-grown gems, they are real, mined stones made in nature.
The Ethics of Mined Diamonds
No one with a heart wants to buy a blood diamond, and there is no excuse for inflicting suffering on people for the sake of a gem, no matter how beautiful. The Diamond Producers Association (DPA), however, points out that the understandable horror at conflict diamonds has blotted out many of the benefits of responsible diamond mining. These include benefits to individuals working in the diamond industry, their communities, and the planet.
Good Jobs and Support for Local Businesses
Good jobs are a priority everywhere, but especially in many of the countries where diamonds are found, which are often underdeveloped. The DPA claims that DPA members employ over 77,000 workers, and that these workers earn, on average, salaries that are 66% higher than their national average. These wages get spread around the local communities through spending by the workers, benefitting people who work in professions outside the mining industry, such as the service industry. In addition, the mining industry itself needs to purchase supplies and pay for services. The DPA claims that $6.8 billion is injected into local economies through the purchase of local goods and services. The small and medium-sized businesses that provide these, in turn, spread the money further by buying their own supplies and services from the community. (For example, a plumber hired to repair a pipe in the local diamond mine will eat lunch at a nearby restaurant, which in turn will buy local produce and hire local staff.)
An example of how diamonds have helped the local economy can be seen in the African nation of Botswana. Before diamonds were discovered there, Botswana was undeveloped, with just three secondary schools throughout the country. Today, there are more than 300 secondary schools in Botswana, and the poverty rate has been cut in half. Free public education is provided to all children up to age 13, after which only a minimum tuition is required, and the government provides education at the University of Botswana to 12,000 students (providing room, board, and a small allowance) and full public scholarships for another 7,000 young people to study overseas. Other benefits include wildlife preserves and healthcare programs. To be sure, as with other fast-growing economies like San Francisco and Silicon Valley in California, Botswana’s development is distorted, with an over-reliance on the diamond sector and the government which diamond mining funds. But while the problem of inequality and diversification are real challenges, there is no question that the diamond industry has helped the overall economic well-being of the country.
Social and Environmental Programs
Responsible diamond mining operations recognize their responsibility to give back to their communities, and often fund healthcare, education, and social programs. DPA members have provided $292 million in benefits to healthcare, educational, and other social programs.
Realizing that diamond mining can impact the environment, they also recognize their responsibility to mitigate that impact through programs that protect the environment. According to the DPA, members protect over three times the land they use and recycle 83% of the water they use in mining. The overwhelming majority of the industry’s waste is rock, which is simply reclaimed by the land.
Carbon Footprint of Mined vs. Lab-Created Diamonds
The carbon footprint of mined diamonds is already far lower than that of lab-grown diamonds, with 69% less carbon emission per carat for natural mined diamonds vs. lab-created diamonds. However, Dr. Evelyn Mervine is working to go farther. She wants to move beyond the goal of a relatively good carbon footprint, towards the goal of becoming 100% carbon-neutral through a new approach using kimberlite, the volcanic rock that diamonds are found in. Kimberlite is a naturally carbon-absorbing substance. Through changes in the disposal of kimberlite waste rock produced during diamond mining operations—changes that increase exposure of the kimberlite to the CO2 in the atmosphere—Dr. Mervine hopes to be able to sequester large amounts of atmospheric carbon in the kimberlite. Through additional approaches, such as using microbes to further increase carbonation of the kimberlite, Dr. Mervine hopes to bring operations to carbon neutrality within 5-10 years.
Responsible Purchasing of Mined Diamonds
Of course, all of these benefits come from responsibly mined diamonds. This is why it is critically important to know the source of the diamonds you buy, and to buy from an organization that takes ethical sourcing seriously. At SuperJeweler, all of the diamonds come from ethical, conflict-free suppliers. All diamonds are bought directly from the source, which not only ensures an ethical supply chain, but also saves you money. With jewelry options from affordable to stunning, as well as loose diamonds, SuperJeweler is a great place to find ethically sourced, earth-created diamonds. At SuperJeweler, you can find the perfect natural diamond for your budget and taste, completing its journey from deep in the earth to you!
Andrew W. Fox is the CEO and CMO of SuperJeweler.com Inc and has 35 years of jewelry industry experience. He is a recognized expert in Diamond Sourcing and Internet Marketing.
Dr. Copeland holds a PhD is in molecular and cellular biology, but she is also an avid history and geology enthusiast. Normally a biomedical writer, she enjoys the chance to write about gemstones and the history and symbolism of jewelry.