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Why Does My Diamond Look Dark?

Why Does My Diamond Look Dark?

Everyone loves diamonds for their magnificent sparkle. Whether they’re set in rings or any other type of jewelry, diamonds will always look oh-so-stunning. 

However, diamonds can sometimes appear to have dark spots within. If you ever asked yourself, “Why does my diamond look dark?” we’re here to provide you with an answer.

A diamond’s environment can significantly impact the looks of the stone – and it can sometimes make it appear dark. But how does the environment affect a diamond’s appearance? And what influences its appearance the most?

All the answers are covered in this article – so, be sure to read it until the end!

How Does The Light Affect Diamond’s Appearance

If you’ve ever asked yourself why your diamond looks different in daylight versus office light, for example, here’s the thing: It happens due to the diamond’s cut responding differently to the light and environment you’re in at the moment.

In short, where and how you look at your stone can significantly alter its appearance.

Think of a diamond as a series of mirrors reflecting the surrounding. That’ll help you understand how location and light can change your stone’s appearance a bit better.

When you look at your diamond, you can see a reflection of the surrounding environment – and yourself – in it.

Often, the dark areas of the pattern you see in a diamond are just reflections of your face or the camera – if you’re looking at a photograph, that is. 

You can test this yourself: 

Hold your diamond at arm’s length; look at how bright the diamond is and observe the patterns of light and dark. Now, slowly bring the diamond closer to your eyes. As it gets closer, the dark pattern within the diamond grows and becomes much more prominent.

That means that, in any given location that you look at your stone in, this series of mirrors inside isn’t reflecting just the environment but you, as well. And how close you hold the diamond – and the environment you’re in – impacts the pattern you see.

When it comes to the GIA’s 4C’s – cut, color, clarity, and carat – cut is often the least understood among diamond shoppers since there are so many factors that go into grading it. 

To help you better understand the diamond’s appearance, we’ll cover the diamond’s cut in more detail. So, be sure to read on!

Learn More: What Light Makes Diamonds Sparkle Most?

A Deeper Dive In The Diamond’s Cut

Diamonds are cut to maximize their brilliance, fire, sparkle – and overall visual appearance of the precious stone. The cut of the diamond is, in essence, a measure of light performance as light strikes the diamond.

Before the process of cutting and polishing is complete, a diamond’s form is known as a rough diamond. Rough diamonds have little to no sparkle due to their lack of facets. Cutting and polishing bring out the sparkle we all know and love.

Diamond’s sparkle and brilliance are a result of light performance. As light hits the gemstone, it pierces the diamond, bounces around and reflects inside the stone, and returns to the viewer’s eyes.

That’s the famous sparkle that you’re able to see. 

And a diamond’s cut directly affects the amount of light performance attained. The size, shape, angles, and location of facets determine the sparkle of a diamond.

Related Read: Which Diamond Cut Sparkles The Most?

Cut Scale: The Factors

Once a diamond is shaped and polished, the cut is then graded. GIA grades the cut by precisely measuring the sizes and angles of the diamond’s facets. These include diamond’s culet, crown, pavilion, girdle, depth, and the table – but symmetry and polishing play a role in the grade, too. 

And all these factors work together to determine the diamond’s cut grade

It’s also worth noting that each diamond size and shape has an ideal cut proportion. So, if you’re looking to buy an ideally-cut gem, talk to one of your local diamond experts – and they can point out some available options.

The Cut Scale

Poor & Fair 

Diamonds with considerable leakage of light will earn a “Poor” or “Fair” grade. These gemstones tend to leak significant amounts of light due to being cut too deep or too shallow.

These stones have minimal brilliance and sparkle and are visually less appealing. 

Surprisingly enough, this category represents 35% of gem-quality diamonds. We’d recommend avoiding these diamonds since they won’t make for sparkling jewelry.


These include well-cut stones that capture light and have high levels of sparkle and brilliance. They still have some leakage of light – but overall shine bright.

Good cut diamonds might have considerably larger or smaller measurements than perfectly cut stones of the same shape. Diamond cutters may intentionally cut stones to Good proportions to attain a particular look and style. 

The top 25% of all diamonds have a “Good” cut grade. 

Good cut stones can offer an excellent blend of value and size. Be careful, though, and ask an expert to evaluate a particular diamond for you before you make a purchase.

Very Good

Very well-cut stones capture almost all of the diamond’s potential. Very brilliant with minimal leakage of light, these diamonds are cut in a way that improves other factors such as clarity, color, and carat weight.

The top 15% of gem-quality diamonds have a “Very Good” grade. 

These stones can be a great option if you’re looking to maximize the value of other aspects of the diamond.


The highest cut grade – “Excellent” – represents the top gem-quality diamonds in the world. 

These diamonds are masterfully and precisely cut to unleash the maximum brilliance and sparkle. Little to no leakage of light occurs as light traverses through the stone. 

This premium cut category represents the top 3% of all gem-quality diamonds.

An Excellent cut stone is always a great choice – regardless of the diamond’s shape or size.

Light Performance

As we explained already, the diamond’s cut reflects the sparkle and brilliance you see from the stone. That sparkle is the light performance of a diamond.

Now, light performance comprises several factors – reflection, refraction, and dispersion. 

The better – and more uniformly – light is reflected, the better the diamond, and the more it’s going to sparkle when set in jewelry.


When a diamond is tilted at different angles, a certain amount of light reflects on the diamond’s surface rather than bouncing within the stone. That is known as reflection. 

Typically, approximately 17% of light is reflected by the diamond. Reflection should be balanced, though. 

When facets are too big, you can see the reflections weaken or strengthen too much, which will lead to diamonds looking dark and dull.

Related Read: Do Black Diamonds Reflect Light And Sparkle?


The perfect diamond is cut so that light enters, bounces, and bends within the stone, after which it leaves through the top of the gem. This concept is called refraction. 

Diamonds have a refractive index of 2.41 – which is pretty high – and that’s what gives them their sparkly characteristics. 

With the ideal cut, the refraction becomes even more noticeable. 

Related Read: Do Diamonds Refract Light?


Have you ever noticed that a stone isn’t white and black, but instead, you can see the colors of the rainbow, all reflecting from the inside of the diamond? 

That’s a result of a concept known as dispersion. 

As light bounces around within a diamond, bends and leaves to the viewer’s eyes, a dispersion is measured at 0.44. That is most commonly known as the fire of a diamond. 

The visibility of all these different colors gives diamonds their unique beauty. Other gemstones usually don’t exhibit the same level of dispersion that diamonds do. 

Therefore, diamonds are considered an excellent and popular option for engagement rings and other types of jewelry.

Finish: Facets, Symmetry, And Polish

Other aspects of the diamond that impact the cut grade are faceting, symmetry, and polish. That said, diamonds are usually cut in two ways – brilliant cuts and step cuts.

Brilliant cuts, most commonly round brilliant cut diamonds or Princess cut diamonds, possess maximum sparkle. They feature more facets than step cuts, and these facets are usually triangular or kite-shaped. 

Brilliant cuts have a high level of sparkle, fire, and scintillation.

Step cuts – like Emerald and Asscher-cut diamonds – are known for their fire and sparkle. They feature facets with a staircase appearance and are slightly simpler in design.

They’re considered elegant, and they maximize the scintillation of the stone. 

But while they’re elegant, these gems have fewer facets than brilliant-cut diamonds. Step cuts exhibit unique beauty; however, it’s essential to consider which type of sparkle you want while picking a cut.

Furthermore, symmetry and polish are a result of the manufacturing process. 

Symmetry is the pattern and evenness of facets’ shape, size, and location. 

If the facets’ position is incorrect, it can impact the light’s performance and thus the cut grade. For instance, an off-center table facet can reduce a diamond’s sparkle.

Polish refers to how cleanly smooth surfaces of facets are. If small polish lines remain after the polishing process, it may impact the light performance – and, therefore, the cut of the diamond. 

Pricing Effect

Like the other C’s, the cut grade can significantly affect pricing. Today, we can see the highest amount of Excellent cut diamonds. The improvement of diamond production technology allows proportions to be more precise in cutting practices.

When it comes to round brilliant cut diamonds, an “Excellent” cut can have up to 10% premium over the next cut grade – which would be “Very Good.” The same goes for “Very Good” to “Good.”

Fancy-shaped diamonds don’t have GIA assigned grades, though. 

That’s because fancy-shaped diamonds come in a range of varying lengths and widths – while still maximizing sparkle and brilliance.

Selecting Cut Grade

The cut is often considered the most important of the 4C’s. When choosing a diamond, it’s vital to find one that doesn’t have light leakage. 

While “Excellent” cuts are the best when it comes to light performance, they’re most expensive.

Very Good cuts, on the other hand, offer more value. The differences in sparkle are subtle – but they are noticeable if you compare the two side by side. 

We always recommend maximizing the cut grade when shopping for a diamond.

Fancy-shaped diamonds have fewer restrictions; their beauty is in the eye of the beholder. 

However, you can often safely go for a lower grade with non-round diamond shapes. Excellent cut fancy-shaped diamonds are pretty rare, though.

Ultimately, which cut grade you choose is up to you. You must remember there’re plenty of other aspects that impact a diamond. So, be sure to consider which factors and attributes matter most to you.

Spread: The Diamond’s True Size

Okay, a diamond’s measurements or spread is arguably the most straightforward concept for consumers to grasp: Diamonds that have a greater spread will also look bigger.

Most cut grading systems don’t count in the spread. That is interesting because it’s the easiest cut-related metric to examine.

While bigger-looking gems aren’t necessarily more sparkly, they tend to be more desirable and sought after among consumers. Two diamonds can have identical carat weights, and still, the one with more extensive measurements will have more spread.

So, as you can guess, the spread isn’t related to the carat weight of the diamond. It’s the total depth percentage that determines the spread in a gem. 

In general, we would recommend stones in the “Excellent” cut grade range with the maximum measurements to achieve the best of both worlds. 

You might end up paying more – but in the end, it’ll be well worth it since you’ll be getting the best of size and sparkle.


“Why does my diamond look dark?” It seems like such a simple question – but the answer, as you can see, is anything but and includes several different aspects of your diamond’s cut and the environment you’re viewing it in, too. 

It’s in the diamond’s nature to reflect its environment, including you, the viewer. Depending on the type of light and environment you’re standing in, your diamond could appear to have dark areas within. The reason behind this is the diamond’s cut. 

A diamond’s cut will impact how well it reflects and refracts the light. And the better the cut, the more sparkle – and brilliance – the diamond will exhibit.

Out of all diamond’s C’s, the cut is the most important. That’s why we’d recommend maximizing the cut grade if you’re looking for the best sparkle and brilliance in a diamond.