What is a Ruby?
Rubies begin as the mineral corundum, chemically known as aluminum oxide (Al2O3).
They are formed when exposed to extreme heat under the earth’s surface. Corundum is usually colorless, but if the aluminum in the corundum is replaced by other minerals, it can take on the colors of the other minerals.
The deep red color of the ruby is the result of the chromium atoms leaking in. If at least 1% of the aluminum atoms are replaced by chromium, the stone will take on a deep red color. If chromium and ferric oxide leaks in the ruby will take on a pink or orange color.
The Burmese Ruby is the most prized of all due to the low iron content in the Burmese earth. The lack of iron accounts for the near fluorescent vibrancy of the gem. Many describe the Burmese Ruby as “having a flame growing within them.”
Many scientists consider the formation of the ruby a miracle of sorts, because of the unlikely conditions the rubies require in order to grow. Rubies grow well in an environment free of silica with low amounts of iron. Since iron and silicon are two of the most plentiful minerals on the planet, the probability of these conditions occurring at the same time is very low indeed. Chromium finding its way into the aluminum crystal makes the ruby formation even less likely.
As a result, rubies are very rare and very costly. For years, man has been looking for a way to create a convincing looking substitute. With the lab-created ruby, they have recreated the real thing, just in a lab setting.
What is a Lab Created Ruby?
Since the time of alchemy, there have been attempts to recreate the ruby. The early alchemist believed the Celestial Ruby was the Philosopher’s stone, a legendary substance that they believed could turn base metals into gold. The ruby was the elixir of life. It symbolized perfection, and enlightenment.
When the practice of alchemy fell into disrepute, so too did the idea of turning metals into gold.
Yet the desire to create a ruby remained.
In 1877, chemist Edmond Fremy developed a method for ruby manufacturing using molten baths of aluminum oxide, yielding the first gemstone quality rubies. Parisian chemist Auguste Verneuil, collaborated with Fremy, but eventually went on independently to develop the flame fusion method, now known as the Verneuil method. Verneuil announce his work in 1902, and published details in 1904.
The Verneuil process begins with the melting of pure aluminum oxide into the Verneuil furnace. The powdered aluminum oxide is placed in a container and then released through an opening in the bottom. From there oxygen is supplied and the alumina and oxygen combination travel down a tube, to another larger tube in which hydrogen is contained. At that point, combustion occurs and the powder melts into smaller droplets which fall on a support rod below.
As more droplets fall, a boule is formed. Eventually, the base of the boule begins to crystallize, and the boule takes the shape of a tapered cylinder. From there, it is removed from the furnace and allowed to cool and split down the middle to relieve pressure.
Although the Verneuil method is still widely used for the manufacture of spinel and synthetic corundum there have been improvements made in ruby synthesis. The Czochralski process, developed in 1917, used most commonly in the semiconductor industry, is capable of producing rubies superior to the Verneuil rubies.
Bell Labs introduced the hydrothermal process in 1957, and in 1958, the Chatham company created rubies using the flux process, the most time efficient method to date.
Here’s how the flux process works:
What is the Difference?
Natural rubies are the ones grown in the earth. They are formed from corundum, or aluminum oxide. They need only to be cut and polished, no other treatments or enhancements are necessary. These are the stones that fetch the high prices.
That said, natural rubies are also highly prone to imperfections. Because the process under which they are created is not controlled or modified, rubies are likely to contain flaws.
Some of these flaws give the stones their beauty; the asteric effect of the star ruby is caused by small needle like inclusions made by rutile, the rare color combinations found in rubies are the result of impurities from the chemicals that seep in.
Other imperfections make the ruby less valuable. Bubble like inclusions can alter the angle of light through the ruby, making them appear opaquer. Other inclusions can make rubies weaker and more likely to chip and break.
Lab created rubies, on the other hand, are created in a lab, under closely controlled conditions.
Like the natural ruby, they too are made from corundum, or aluminum oxide. The growth process is monitored, and therefore, the stone can be created with all the desired attributes.
While lab rubies possess chemical, optical, and physical properties identical to a natural ruby, the irrelevant inclusions found in natural rubies are not present in lab grown rubies. They are also much cheaper than natural rubies.
To be clear, a lab created Ruby is the exact same chemical composition of a natural ruby, the difference is simply that the lab created ruby was made under controlled conditions of a lab.
Let’s look at a side by side comparison of the features of the lab grown ruby as compared to the natural ruby.
Difference in Hardness
The Moh’s scale is the standard scale of hardness used to classify minerals. It runs from one to ten. Although when we think of hardness, we tend to think of something solid and firm, the Moh’s scale judges a mineral’s hardness by its ability to scratch another mineral.
According to the Moh’s scale the diamond is the hardest material known to man. It rates a ten on the Moh’s scale. There is no material capable of scratching the diamond and there is no material it is incapable of scratching.
The second hardest mineral, rating a nine on the Moh’s scale is corundum, the mineral that makes up the ruby and the sapphire. Part of the appeal of the ruby is its ability to withstand strenuous conditions. The ruby is not only valued for its beauty, but its durability as well.
The lab created ruby is also made of corundum and stands up to wear and tear equally. The natural ruby is likely to contain flaws, many of which can weaken the crystal, causing it to become brittle.
Because lab created rubies are made in a controlled environment, many of the flaws can be eliminated, making the rubies more resistant to the conditions of daily life and essentially a flawless replication.
Lab created rubies are identical in chemical composition to natural rubies and identical according to the Moh’s scale.
Difference in Clarity
Even though it takes super high-powered equipment to spot it, the difference in clarity is what usually gives away the lab created ruby. But it’s not necessarily a bad thing though.
Because lab created rubies are made in a controlled setting, it’s unlikely they will have imperfections. But naturally occurring rubies almost always have imperfections.
So, a lab created ruby being inspected by a jeweler can be spotted because it’s more prone to be flawless, but to anyone with the naked eye a lab created ruby is absolutely stunning due to this.
Clarity refers to a gem’s transparency and its ability to transmit light. All -natural rubies are Type II in clarity, which means they contain inclusions, or flaws.
Inclusions are the fractures and liquids, gasses and crystals of other minerals in trapped in the structure of the ruby as it forms. Some of these can enhance the quality of a ruby, others can diminish it.
Because rubies are never without inclusions, the highest quality natural rubies one can hope for are rubies clarity graded VVS (very, very small inclusions), or what gemologists refer to as ‘loupe clean.” This means that even when examined with a 10x loupe, no inclusions can be spotted.
Loupe clean natural rubies are extremely rare and finding one in any size over one carat is a challenge.
Finding a lab created ruby that is “loupe clean” is much less of a challenge. Because lab rubies are grown in a controlled environment, internal flaws can be minimized. As a result, lab created rubies tend to have better clarity and less or no inclusions.
Difference in Color
According to the GIA color grading system, there are three elements to color: hue, tone, and saturations. The basic hues are red, orange, yellow, blue, green, violet, and purple. Tone refers to the lightness or darkness of the stone, from colorless (0) to black (10). Saturation is the intensity of the color, ranging from grayish (1) to vivid (6).
Since there are rarely pure hues in nature, there are often secondary hues used to describe rubies as well. Rubies may exhibit a variety of secondary hues, such as orange, pink, violet, and purple.
Top rubies display a hue of red (R), a tone of 6 and a saturation of 6. This combination would be noted as R/6/6. Only gems form the corundum family can reach such deep levels of saturation.
Because the lab created ruby is also made of corundum, it too can reach such intense saturation. Most lab created rubies are deeply vivid and rich in color.
As is the case with the natural ruby, the color in lab created rubies is the result of the combination of aluminum oxide with chromium. Other minerals such as titanium, rutile, vanadium, and iron may also be added to produce variations in clarity and depth of color, including the most sought-after pigeon’s blood red.
Difference in Sparkle and Fire
Everyone loves the rubies that shine the most, but there’s more to the “sparkling” than meets the eye. The sparkle of a gem refers to the amount of white light it refracts. The fire of a ruby has to do with the degree to which it disperses white light into spectral colors.
The diamond is a stone known for its sparkle. It has a refractive index of 2.417, an extremely high number in comparison to most other gems. A clear diamond sparkles a lot because the light entering the diamond is reflected many times.
The dispersion of a diamond is comparatively high. Because the inside of the stone will sparkle gray and white, the outside of the stone will reflect rainbow colors on other surfaces, giving it a dispersal rate of 0.444.
In rubies, the prime color is red. Although, like the diamond, the ruby does reflect other colors, in the ruby these are usually tinges of purple and orange. Because the rubies do not reflect the full spectrum of light, their refractive index and dispersion are lower than that of the diamond. The refractive index of a ruby is 1.76 -1.77. The dispersion of rubies is 1.018.
Another way that diamonds differ from rubies is that rubies exhibit pleochrism. That means that the way they are cut can cause them to exhibit certain colors and reflect light in certain ways. The art of cutting a ruby requires a trained eye.
Because a lab created ruby is cut with the same expertise as the natural ruby and is identical in chemical composition to the natural ruby, you can expect to see the same tints of color and sparkle that make the natural rubies so beautiful and unique from one another.
If brilliance and fire are high priority on your list, you’ll find a lab created ruby will live up to your expectations.
Lab Created Ruby or the Natural Ruby: Which is Better?
All in all, it’s not about which one is better, but which one is better for you. Of course, there are the purists among us who believe that a ruby created in a lab can never be as valuable as real ruby, but those people also tend to have huge pocketbooks.
The truth is that most of us will find it difficult to ever afford a real ruby. Elizabeth Taylor’s rubies cost astounding amounts and even though Liz had a reputation for extravagance, finding natural eye clean rubies at sizes of over a carat are hard to come by.
If it comes down to never wearing a ruby or wearing a lab created ruby, the lab created ruby is the obvious choice. Every woman should have the chance to wear a ruby, and lab created rubies are impossible to distinguish from natural rubies without a 10x magnification by a jeweler, and even then, they’ll just notice that the ruby has no imperfections, which is hard to see as a negative characteristic.
Now that you’ve gotten the lowdown on natural rubies and lab created rubies, which would you chose? Would you hold out for the natural ruby when you could be wearing a lab created ruby at a much more affordable price?
