Natural Diamonds vs Lab Synthesized Diamonds vs Simulated Diamonds

Diamonds

My boyfriend Jeremy proposed to me! (Yay!) Which means I am now on an engagement ring hunt. (He proposed without a ring, so that we could look at rings together, and I could get exactly what I wanted.)

I actually do not want a diamond engagement ring. Diamonds are overdone. Diamonds are not as rare as the diamond cartels want you to believe. And I simply do not want to be a shill for the diamond industry. I might write about how I feel about the diamond industry in a later blog. But suffice it to say, I will be getting a sapphire engagement ring. We are currently in the process of getting a sapphire custom cut, and I hope to show pictures of it soon!

Although I am looking at sapphires for my stone, you can't really get an engagement ring without having diamonds forced at you on every website, every ad, etc. And when looking at engagement ring settings, they are always always shown with diamonds. So I notice diamonds. In particular, my fiance and I noticed this ad (in a car magazine no less!):

It is an ad for what they call "DiamondAura." And it's priced at less than $100 per carat. (compared to real diamonds that sell for thousands of dollars per carat.) That's a huge tip off that its not a natural diamond. But I originally thought it was a synthetic lab grown diamond. Jeremy caught the fact that it's not even a lab grown diamond. It's not a diamond at all. Hidden deep in the text, the ad informs you that it is a "diamond simulation."

And this made me curious about simulated diamonds vs Lab synthesized diamonds vs natural diamonds.

Natural Diamonds

So we will start by defining a diamond.

Diamonds are made of carbon atoms arranged in a face-centered cubic crystal structure (a diamond lattice). Due to the strong covalent bonds between carbon atoms, diamond has incredible hardness (10 on the MOH's scale). There are often impurities in natural diamonds, and small amounts of impurities can give diamonds different colors.

• nitrogen impurities --> yellow diamond (most common impurity)
• boron impurities --> blue diamond

Other defects can create other colors

• defects in lattice orientation --> brown diamond (creatively rebranded by the diamond industry as "chocolate" diamonds)
• radiation exposure --> green, red, pink, purple diamonds

Diamonds are formed at high temperatures and high pressures, typically deep in the Earth's mantel. Growth can occur over billions of years deep inside the Earth. Reserves of diamonds are periodically brought up to the surface to depths that can be mined during geologic shifts such as volcanic eruptions.

In nature, white diamonds are very common. (Off white diamonds with a slight yellow tint are the most common.) The so called "Fancy" colors are very rare and command a very high price per carat. Yellow Fancys are the most common of these, Blue is very rare, and only a handful of Red diamonds exist.

Synthetic Lab Created Diamonds

Diamonds can be produced synthetically in a high pressure, high temperature (HPHT) process that simulates the high pressure, high temperature conditions in the Earth's mantle. An alternative growth technique that does not require these high temperatures and high pressures is chemical vapor deposition.

Lab created diamonds are diamonds in that they are made of carbon atoms arranged in a diamond lattice. They have the same properties (hardness, clarity, scintillation) as natural diamonds, but often have different impurities due to the method of creation in a laboratory setting.

Synthetic Diamond Colors

White synthetic lab created diamonds are rare, due to limitations in the manufacturing process. The lab can very easily create yellow and blue diamonds (which are conversely very rarely found in nature), however white diamonds are difficult to synthesize. As a result, the price of white synthetic diamonds (as of 2014) is almost the same as the cost of a natural diamond.

Diamonds grown using high pressure, high temperature most often develop Fancy yellow colors due to nitrogen in the diamond's crystal lattice. Nitrogen acts as a catalyst, encouraging crystal growth. As a result, a yellow diamond can be grown in a mater of 3-6 days. They typically range up to 2 cts, with some as large as 4 cts.

Blue diamonds are grown due to boron trapping in the diamond lattice. Boron also acts as a catalyst and facilitates growth, but growth is slower than yellow, and therefore synthetic blue diamonds cost more than yellows. Blue diamonds require about 7-10 days and are available up to about 1.5 ct.

Colorless white diamonds must be grown in the absence of any catalyst (no nitrogen, no boron). The speed of crystal growth is much slower (10-14 days), so white diamonds require longer incubations in high heat and high temperatures. The extra energy, resources, and time required to produce colorless diamonds make them comparatively more expensive to produce. Energy costs alone can become very high for production of a single diamond. Additionally, the long time required to grow colorless diamonds allows more opportunity for inclusions and impurities that would impart color and "ruin" the diamond. Being the most difficult to grow, white diamonds are limited to about 1 ct.

Other colors such as pink, purple, red, and green can be obtained by irradiation the diamond. Irradiation is a procedure where the diamond is bombarded with electrons which alter the diamond's crystal lattice.

The alternate process of producing diamonds called Chemical Vapor Deposition (CVD) requires the use of carbon ladened gasses such as methane in a low pressure, heated environment. A small diamond seed is used to initiate crystalization. Using microwaves as an energy source, the carbon in the methane gas is broken apart, and bonds to the diamond seed.

CVD commonly produces brownish to near colorless diamonds (depending on the perfection of the lattice produced, with more imperfect lattices appearing browner.) Many CVD diamonds often undergo a second round of high pressure, high temperature treatment to turn brownish or off-white diamonds into more desirable colorless diamonds.

Lab created diamonds can be of very high quality. They can have exceptional cut, color, and quality. And some would argue that lab created diamonds are harder or otherwise "better" than natural diamonds, in that there can be fewer impurities and inclusions.

Colorless lab grown diamonds are pretty close to the prices of their natural counterparts. This often surprises people. Many people may have been exposed to very cheap imitation diamonds (see below), and assumed they were lab grown diamonds. Others may be familiar with synthetic sapphires, rubies, emeralds, or other gemstones which are all fairly inexpensive compared to their natural counterparts. However, diamonds are different.

Costs of Cutting Synthetic Diamonds

Cutting a diamond rough into a finished gem is very difficult, takes specialized equipment, and very skilled artisans. Diamonds are harder than any other gem, therefore diamonds must be cut with other diamonds. The labor is as intensive for synthetic diamond as it is for natural diamond. And synthetic diamonds still must be cut one at a time. Depending on the stone, up to half of the cost can be directly attributed to the cutting process. The other half goes to the costs to mine or grow the diamond, distribution channels, grading labs, appraisers, advertisers, and everyone else along the distribution chain.

Costs of Growing Synthetic Diamonds

Synthetic diamonds start out small and grow slowly over time. The machines for making synthetic diamonds are capable of growing only a few carats a week. And the difficulty of growing increases exponentially with size. It is easy to make little diamonds necessary for the industrial market. But larger diamonds for the gemstone jewelry business are much more difficult, as they need to be larger and relatively pure. Diamonds are cut by hand to minimize waste. A breakthrough in technology is required for the price of synthetic diamonds to drop drastically.

In comparison, synthetic sapphires are huge (the size of a potato or soccer ball). They can be grown thousands at a time, and can be cut in an automated manner, as waste is not an issue.

The initial capital investment (for specialized equipment to produce the diamonds and engineers and scientists required to perfect the process), as well as the labor and energy for each machine cycle to produce one diamond are very costly. Once the diamond is grown, it is cut and graded just like any other diamond. These factors all play into the cost of lab grown diamonds, making them retail for about $5000 per carat.

Simulated Diamonds

Diamond simulants are NOT diamonds. They are Imitation diamonds. They are not made of carbon, do not have the same structure as a diamond, and do not have the same chemical, physical, or optical properties of a diamond. Similants are simply things that superficially look similar to diamonds and may be mistaken as diamonds to an uneducated observer.

There are many companies selling simulants and trying to pass them off as synthetic/lab created/man-made diamonds. (See the ad I referenced above. They use ambiguous terms like "chemistry," "scientific process," "lab created", "perfection from the laboratory" to make customers believe that it is a true lab created diamond, when in fact they are selling a cheap simulant that is actually just a diamond coated cubic zirconium.) They often use very confusing or deliberately misleading terminology.

Commonly used simulants include cubic zirconium, diamond coated cubic zirconium, moissanite, and others.

If you ever see a product claiming to be a synthetic white diamond priced at something as low as $100/ct, then it is very very likely a simulant. As I've mentioned above, lab created white diamonds are rare, and as of 2014, cost almost the same as a natural diamond, perhaps slightly less.

Diamond is the hardest substance known, and is harder and more durable than any simulant.

Cubic zirconium is the most popular diamond simulant. It is the cheapest and most diamond-like of all simulants. A properly cut CZ looks almost indistinguishable from a similarly cut diamond. There are differences in hardness and thermal conductivity if you analyze them. Abraded and dirty CZ do look different than diamonds, as they wear differently. They also do not last very long in rings without damage, as they are much softer than diamonds. If you see any simulant with a clever name like "Diamonique" or "Diamond Nexus" it's safe to assume that it is CZ. Dishonest sellers will buy $5 CZ and resell it as "diamond" for $100. Anything that is ambiguous about what it is and seems mysteriously cheap is most likely CZ.

There are natural deposits of cubic zirconium, but all of the cheap CZ sold as diamond simulants are synthetic. CZ weighs about 1.6 times as heavy as diamond, but is more brittle and less hard (Mohs scale 8), less sparkly, but has more prismatic fire. CZ is almost always perfectly clear in color, whereas natural diamonds routinely have impurities and slight tints in color.

Moissanite has a higher refractive index and dispersion than diamond, and offers more "fire" than diamonds. However, it often has a slight green tint, and actually exhibits bi-refraction, which may make it look "fuzzy," as opposed to the crisp look of a well cut diamond.

Moissanite can be found naturally in mineral deposits, but most jewelry moissanite is artificially made. It is very hard with a Mohs scale of 9.25. It is lighter in weight than diamond, but is sparklier and has more prismatic fire.

Natural gemstones with the look of diamonds include white sapphire, white topaz, and zircon. However, these are always sold as natural sapphire/topaz/zircon, as they can be expensive, are beautiful stones in their own right, and are hard to pass off as a diamond.

Glass is another simulant in very cheap jewelry, but does not really fool anyone as being true diamond.

Swarovski Crystal is a form of glass that is made at high temperatures by melting silicon oxide with lead to form lead crystal. It has approximately 32% lead content to increase the crystal's refraction index to resemble diamond. The crystal is precision cut and polished to give it a high quality finish and enhanced by coating the glass with an AB (Aurora Borealis) coating that gives the surface a rainbow like appearance to simulate dispersion from a diamond. Swarovski crystal has a Mohs hardness of 6=7, so it is susceptible to scratches and chipping, but is still harder than standard glass.

Off Topic Personal Rant

Diamonds will probably always be expensive, and there are fakes that are pretty good and very inexpensive. Whether you want to purchase a diamond imitation instead of a real diamond really depends on your purpose. I believe that if you really like the style of diamond jewelry and want to buy CZ as a cheaper alternative, that is fine as long as you are not misrepresenting yourself. If you like the look of moissanite, white sapphire, white topaz, glass, etc, then buy it and wear it with pride. Those gems are beautiful enough as themselves that you shouldn't feel the need to lie and call it diamond.

If your purpose is to get something that looks like diamond to impress an onlooker, then there are definitely cheaper ways to get the same result. CZ looks as good as diamond until it scratches, gold plating looks as good as 18k gold until the plating wears off, steel looks similar to platinum until it rusts. If you feel the need to lie to others to impress them with your poor quality replicas, then you really need to re-evaluate why that matters so much to you.

Identification

Although lab created diamonds and natural diamonds look identical to the naked eye, all lab created diamonds (0.3 cts and above) from reputable companies are laser engraved with a microscopic serial number that starts with "LG," which stands for "Laboratory Grown." Even without a serial number, any reputable gemological laboratory is able to distinguish between a natural diamond and a lab created diamond.

A thermal diamond tester will identify real diamonds (both natural and synthetic) from simulants such as cubic zirconium, as they are made of different materials. Electrical conductivity tests can detect electrically conductive Moissanite from white/yellow diamonds that are non conductive. All blue diamonds (both natural and synthetic), are electrically conductive.

More advanced tests can distinguish synthetic diamonds from natural diamonds. HPHT diamonds grow in a molten metal solution, so their inclusions are metallic. Mined natural diamonds grow in molten rock, and do not have metal inclusions. Infrared (FTIR), ultraviolet, or x-ray fluorescence (EDXRF) spectroscopy is able to detect trace impurities of iron, cobalt, nickel, or other metals that are present only in lab grown diamonds. Synthetic diamonds grow in both octahedral and cubic lattices, where natural diamonds only have octahedral symmetry.

Conclusion

Do not be fooled by companies trying to sell simulated diamonds as lab created diamonds. Most simulated diamonds are actually just cubic zirconium, which is worth only $5/ct. Companies attempt to give their cubic zirconium an ambiguous name name like "DiamondAura" or "Diamonique" to avoid explicitly calling it a diamond (which it is not), but at the same time avoid calling it cubic zirconium. They are in fact trying to sell you a $5 cubic zirconium for $100 per carat, and calling it a deal! These diamonds are not real, and their business practices are shady at best. They make a living off ambiguity and deceit and taking money from uneducated customers. Do not be fooled! If something diamond-like is less than $1000 per carat, it is NOT a diamond. You should feel free to buy cubic zirconium if what you want is cubic zirconium. Cubic zirconium is beautiful in its own right, and does make spectacular jewelry. I just hate the idea of companies selling you overpriced cubic zirconium when you think you are getting synthetic diamond.

Synthetic lab grown diamond is a good alternative if you are in the market for a Fancy diamond. Colored or "Fancy" synthetic diamonds are much more abundant and much cheaper than the Fancy natural diamond counterparts. Natural blue diamonds especially are very expensive, reaching over $25,000 per carat for a very desirable blue color. Compared to a synthetic blue at around $5000 per carat, the synthetic is much more affordable. The same is for fancy yellow diamonds, although the difference is slightly less, as natural yellow diamonds are more common than blues, but still rare and expensive for deep yellow colors.

For white diamonds, however, the difference between lab synthesized and natural is smaller, with the synthetic diamonds only a few hundred dollars cheaper on average. Lab grown diamonds can, however, be made with higher clarity, fewer inclusions, and clearer color than natural diamonds, so if you compare lab grown diamond with a natural of the same Cut, Clarity, Color, and Carat, the lab grown may be substantially cheaper at the high end of the diamond spectrum where natural diamonds get exponentially more expensive. But a technological breakthrough is required before we see very low synthetic clear diamond prices. (Edit: This post was written in 2014. The cost differences may grow larger over time as lab synthetics grow cheaper, and I would check prices before making a decision.)

For those looking for cheaper white diamonds, I would recommend searching for estate or second hand natural diamonds instead. For people concerned about "blood diamonds" and labor or mining conflicts, there are conflict free natural alternatives from diamond mines in Canada, Australia, Russia, and other regions.