Nowadays, many gemstones on the market were not mined from the earth but made in laboratories with human aid in controlled conditions. Ruby is not an exception. That is why if you are about to buy a ruby, you may want to understand the difference between lab-created rubies vs natural rubies.
Lab-Created Rubies vs Natural Rubies Composition
Natural rubies are formed under immense pressure and intense heat under the earth’s surface for millions of years. They consist of oxygen atoms called corundum and aluminium, which turn into liquid under heat and pressure and seep into cracks in igneous or metamorphic rocks. When the liquid cools, it usually turns into colourless crystals. However, when minuscule traces of other minerals mix with corundum, they turn it into reds, pinks, blues and yellows. If the microelement is chromium, then the corundum turns red, and we get rubies. In the case of iron and titanium, we get blue sapphires.
Natural rubies require unlikely conditions to grow. They need an environment free of silica with low amounts of iron. However, since iron and silica are the two most abundant minerals on the planet, the probability of these conditions occurring at the same time is very low. Moreover, chromium finding its way into corundum and aluminium crystals makes the ruby formation even less likely. As a result, natural rubies are very rare and expensive, which made man looking for a way to create a relatively affordable alternative.
Lab-created rubies, also known as created, lab-grown, synthetic, cultured or man-made rubies, are gemstones grown in laboratories with human aid under controlled environments. They have identical chemical compositions to their natural counterparts (Al2O3) and the same optical and physical properties.
Since natural rubies are formed in uncontrolled conditions, they are highly prone to imperfections. Unlike natural gems, the growth process of lab-created rubies is highly monitored, meaning the stone can be created with all the desired attributes. With this in mind, lab-created rubies are more resistant to the conditions of daily life, although both natural and lab-grown rubies have a rating of 9 on the Mohs scale of hardness.
Lab-Created Rubies vs Natural Rubies Colour and Clarity
Colour is the most important quality factor affecting a ruby’s value. The most desirable and sought-after ruby colours are strong, pure red and red with a hint of purple.
As in the case with natural ruby, the colour of lab-created ruby is the result of the combination of aluminium oxide with chromium, which is why lab-created rubies can also reach intense saturation (colour intensity) and mostly have deeply vivid and rich colour.
Clarity is what usually gives away the lab-created ruby. Since synthetic rubies are created in controlled conditions, they commonly have fewer imperfections than their natural counterparts. That is why a professional can always spot the difference using a 10x loupe or a microscope.
The process of growing synthetic gems leaves certain traces in the stone that can also help identify lab-created rubies. For example, tiny amounts of lead indicate that the stone was created in a lab.
All rubies have structural patterns or “growth lines” that occur during their formation. Structural patterns in lab-grown rubies are characteristically curved, indicating their artificial origin. Created rubies may also have gas bubbles inside, which form during the manufacturing process.
How to Identify Lab-Created Rubies
If you do not have an option to send your ruby to a laboratory for testing, you may try to identify its origin by following these tips. However, keep in mind that these clues may not be 100% accurate for all the cases.
Since synthetic rubies are created in labs in a controlled process, they have higher clarity than most natural rubies. This does not mean that all flawless rubies are necessarily artificial, but if a stone of a high clarity grade is natural, it will be very expensive and hard to find. So if a high-clarity ruby is significantly cheaper than an identical natural stone, then most likely, you are dealing with a lab-created ruby.
Another sign that ruby is lab-grown is its size. Large natural rubies are rare and very pricy as a result. For example, a 2-carat ruby is harder to find in nature than to create synthetically. So if a ruby is quite large and still affordable, it is likely to be artificial.
Considering the above, the low price is proof that the stone might be synthetic. If a ruby has an intense red colour, high clarity, large size and relatively low cost, it is most likely not natural.