Lab grown diamonds are a great option for those who want a fine diamond at an affordable price. Environmentally friendly and ethically sourced, man-made diamonds are perfect for jewellery and are slowly but surely gaining popularity.
While we’ve discussed much of the confusion around lab grown diamonds on our other blogs, one question is still a little unclear (yes, that pun is intended): Do lab grown diamonds have inclusions? Read on to find out.
In natural diamonds, deep underground, these imperfections are developed from irregular crystal growth or other materials being trapped inside the diamond during its forming process.
It’s important to remember that lab grown diamonds have the same chemical and physical properties as natural mined diamonds. Lab diamonds begin as a small diamond seed, made of pure diamond, and carbon attaches to grow more layers of a diamond.
Learn more: How are man made diamonds created?
Overview:
- How Do Inclusions Form In HPHT Diamonds?
- How Do Inclusions Form in CVD Diamonds?
- What Is Clarity In A Diamond?
- Clarity Treatment in Diamonds
Do Lab Grown Diamonds Have Inclusions?
So, do lab grown diamonds have inclusions? The answer is yes, lab grown diamonds have inclusions just like natural mined diamonds do. Inclusions are the tiny imperfections that occur naturally in all forms of diamonds. In mined diamonds, inclusions can take on a variety of forms, all of which contribute to hazy or distorted effects on the final cut diamond — though sometimes they are hardly noticeable.
Inclusions occur when something foreign is trapped inside the diamond while it's forming, such as another mineral or an inclusion of air. Scratches, pits and discoloration are also considered inclusions.
One of the key ways to identify natural and lab diamonds is in their inclusions but you generally won’t be able to tell the difference between the two.
Learn more: What's the difference between lab diamonds and real diamonds?
How Do Inclusions Form In HPHT Diamonds?
HPHT diamonds are formed under enormous pressure and heat. This process replicates the forming of a natural diamond deep underground, but has some key differences that affect how inclusions form.
To pressurise and heat carbon atoms to the point where they attach to a diamond seed and begin to grow, the presence of other metals is required. Essentially, metals like iron, nickel or cobalt help carbon transfer from the source of carbon (such as graphite) to the cooler diamond seed. Bear with us, this is all a little complicated but you’ll see in a moment how it changes the appearance of inclusions.
These metals, contained in the HPHT diamond forming capsule, can sometimes be trapped underneath layers of diamond—and in large amounts will create inclusions that can be seen by the naked eye.
Inclusions containing iron, nickel or cobalt form a little differently to the inclusions you see in mined diamonds. They can appear metallic and reflective, they can have a white, grey or black colour and come in a range of shapes forming from straight lines. Sometimes inclusions found in HPHT aren’t big enough to see, but can help a gemologist to identify how the diamond is made.
Today, jewellery quality HPHT diamonds won’t often have noticeable inclusions. This process of growing diamonds has been practiced since the 1950s, but new technological improvements and more care is being put into creating these gorgeous stones than ever before.
How Do Inclusions Form in CVD Diamonds?
Unlike HPHT diamonds, CVD diamonds don’t require the presence of metals like iron and nickel to grow. Instead, these diamonds are grown using carbon-rich gasses such as methane.
This gas is pumped into a box with diamond seeds sitting on a platform, and heated using microwaves. This causes the carbon atoms to separate from the gas, and attach to the diamond seed in layers. This process can take weeks to a month to grow a diamond over a carat in size.
Much care is taken by scientists to ensure that each time a new layer of diamond is grown, the stone is polished and cleaned. This reduces the chance of outside minerals getting trapped in the layers of diamond as they grow. Unfortunately not every diamond can be flawless though.
Inclusions in CVD diamonds will look different from the ones you see in HPHT lab diamonds. For one, they won’t have any of the metallic lustre that can appear in an included HPHT diamond. Most commonly, carbon-based graphite appears inside CVD diamonds, which takes on a dark crystal appearance. These non-metallic inclusions don’t have a straight line appearance, but can be seen as cloudy formations of black carbon crystals.
So now you know that lab grown diamonds can have inclusions. Let’s look at how that relates to the 4Cs of diamond grading.
What Is Clarity In A Diamond?
Clarity is one of the ‘4Cs’ used to grade the quality of diamonds. Along with colour, cut and carats (or size), clarity can have a big impact on the overall price of a gemstone.
Clarity refers to the presence and visibility of internal flaws. The clarity of a diamond is assessed by a skilled grader when it is being professionally appraised, and you will be able to see this testing when buying a diamond piece. As a rule, the more flaws you see in the diamond, the lower the clarity grade.
Diamonds are given a clarity rating from ‘imperfect’ all the way to ‘flawless’, but will usually have some form of inclusion — less than 0.5% of diamonds end up with a flawless clarity grading.
We should note that the presence of one or more inclusions alone won’t dramatically lower diamond prices. Sometimes inclusions are small enough or positioned somewhere where you won’t be able to see them when worn. No diamond is ever the same, and the tiniest of inclusions might help you identify your piece without taking away from its beauty.
Learn more:
Clarity Treatment in Diamonds
Sometimes stones are treated before going into jewellery, to remove the colour or presence of clarity and improve the overall value. These diamonds should be labelled as ‘clarity enhanced’ and like colour treated diamonds, they have been met with some scepticism.
The obvious benefit of clarity treatment is that a stone with a dark or highly noticeable inclusion can be greatly improved. What makes them a little controversial is that clarity enhanced diamonds are sometimes sold at the same price as a non-treated diamond with the same clarity. There are a couple methods used for enhancing clarity in diamonds, and we’ll get into the benefits and problems with both.
Laser Drilling Treatment
A laser drill can be used to remove big or dark inclusions that dramatically reduce the clarity of a diamond. This is done by drilling a thin tunnel from the surface of the diamond to the inclusion using a laser.
From there, these chemical solutions are transported through the tunnel to dissolve or bleach the cause of the inclusion. While this will improve the appearance of the inclusion, it will also leave a very small line left by the tunneling. The hole left by the laser can also fill with outside minerals and may discolour slightly. The second method of fracture filling can be applied here to fill the tunnel left by the laser drilling process.
Fracture Filling Treatment
Diamond fractures can be filled with molten glass or a glass-like liquid. This process will make gaps in the diamond much less visible, and improve the overall clarity of the diamond. There’s a few negatives to this method: one is that your diamond will no longer be made of pure diamond as the filling is a glass-like substance.
Another issue is that fracture filling doesn’t last forever. Fillings can last around one or two years, but may fade or discolour, and are hard to repair after that. If the filling leaks out, it is possible for it to be repaired, but truthfully the constant repair and work that fracture filling takes makes it an unreliable option for diamond enhancement.
To wrap it all up, Inclusions don’t necessarily ruin a diamond. There are many diamond jewellery pieces that have minor inclusions that aren’t any less beautiful. Lab diamonds don’t commonly have very noticeable inclusions either, as they are monitored for the highest quality possible.
It’s always a good idea to check the clarity grading of a diamond before you buy it, and check if it has been clarity enhanced, too. Remember each and every diamond is unique, and you can think of inclusions as birthmarks that tell you a bit about the history of the diamond.