5 Reasons Why Diamonds Can Look Cloudy (Plus Fix)

Diamonds, coveted across the globe for their enchanting brilliance and supreme hardness, have long symbolized affluence, love, and commitment. As the hardest known natural substance, the allure of diamonds is multi-faceted, just like the precious stones themselves. However, many diamond owners and potential buyers alike often wonder about a commonly observed phenomenon – the cloudy appearance of some diamonds. While these gemstones are renowned for their crystal-clear allure, why do some diamonds seem to lack this celebrated clarity? This blog will delve into the enigmatic world of diamonds to uncover the truth behind their occasionally cloudy appearance.

The complexity of a diamond’s clarity involves a nuanced understanding of gemology. Various intrinsic and extrinsic factors can influence a diamond’s ‘clear’ reputation. They include but are not limited to, the presence of natural impurities, inclusions or blemishes, the quality of the cut, and even everyday grime and dirt.

However, fear not diamond enthusiasts! A cloudy diamond is not a cause for alarm, and it’s not a lifelong sentence. There are a plethora of professional and at-home remedies that can rejuvenate a diamond’s inherent brilliance and sparkle. Through this enlightening journey, we’ll uncover why diamonds look cloudy and introduce you to effective methods for reviving the dazzling sparkle in your cherished gemstones. Whether you’re a diamond aficionado, a prospective buyer, or simply curious, join us as we shed light on this fascinating facet of gemology.

Reasons Why Diamonds Can Look Cloudy

UV Sunlight

Ultraviolet (UV) light can play an interesting role in the appearance of diamonds, often leading to a perceived cloudiness or change in color. However, this cloudiness is not a physical alteration to the diamond itself, but rather an optical effect due to the diamond’s interaction with UV light.

Diamonds are composed of carbon atoms arranged in a tightly knit crystal lattice. Some diamonds, during their formation deep within the Earth’s mantle, may have trapped within them certain impurities like boron or nitrogen atoms. Nitrogen, in particular, can absorb UV light and subsequently re-emit this energy as visible light—a process known as fluorescence.

When a diamond exhibits strong fluorescence, it can glow bluish-white under UV light, like the kind present in sunlight or blacklight. For a diamond with a high level of fluorescence, this can sometimes result in an oily or hazy appearance, giving the impression that the diamond is “cloudy” when viewed in natural daylight or under certain types of artificial lighting with strong UV components.

However, it’s essential to note that this cloudiness is not always considered a downside. In some cases, fluorescence can enhance the appearance of a diamond with a lower colour grade, making it look whiter than it actually is. Nevertheless, for higher colour grade diamonds, strong fluorescence might result in a perceived reduction in transparency and thus make the diamond appear cloudy.

It’s also worth noting that only a small percentage of diamonds exhibit strong fluorescence, and among these, only a fraction will display this hazy or oily appearance. Most diamonds, even those with fluorescence, will not look cloudy under most light conditions. Hence, the impact of UV light on a diamond’s appearance is highly individual and should be considered on a case-by-case basis.


While diamonds are renowned for their hardy nature and enduring shine, they are not immune to the effects of daily wear and tear. One common culprit that can dim a diamond’s dazzling sparkle is simple, everyday dirt.

Diamonds, by nature, are incredible grease attractors. When a diamond comes into contact with substances like oils from our skin, lotions, makeup, or even dust in the air, these substances can stick to the diamond’s surface. Over time, this accumulation forms a film of dirt and grime that dulls the diamond’s brilliance, thereby giving it a cloudy or dull appearance.

Diamonds’ most attractive quality, their ability to refract and reflect light, can be significantly hindered by this film. Light, instead of passing through the diamond and bouncing back to the viewer’s eye, gets diffused by the layer of dirt. This prevents the light from interacting with the diamond’s facets as intended, resulting in the diamond losing its sparkle and appearing cloudy or dull.

The effect is particularly noticeable with dirty diamonds because of their high refractive index – diamonds interact with light differently than most other substances, bending it to a significant degree. This is what gives a clean diamond its characteristic sparkle. When the surface of the diamond is covered in dirt or grime, that light interaction is disrupted, and the diamond can seem to have lost its luster and clarity.

Fortunately, this cloudiness is not permanent and can be easily remedied with regular cleaning to maintain the diamond’s beauty and brilliance. Whether it’s a gentle scrub at home or a professional cleaning, the sparkle of a diamond can be restored, proving once again why diamonds are a cherished treasure.


Similar to the effect of dirt, the accumulation of grease or oils on a diamond can significantly diminish its sparkle, making it appear cloudy or dull. The explanation for this lies in the very nature of how diamonds interact with light, and what happens when that interaction is interrupted.

Diamonds have a high refractive index, which means they bend light to a great degree, more than most other substances. This property, combined with a properly executed cut with many facets, allows the diamond to reflect and refract light in a captivating manner, creating that highly desired sparkle.

When a diamond comes into contact with grease or oil, however, a film forms on its surface. This could be body oil from handling, cooking oil from food preparation, or even natural oils from our skin. This film of grease or oil changes the way light interacts with the diamond. Instead of light entering the diamond, being refracted, reflected off the internal facets, and exiting back to the viewer’s eye, the light is instead diffused by the grease on the surface.

This diffusion of light creates a dull, cloudy effect, as the light isn’t being effectively bent and reflected by the diamond. The stone’s scintillation and fire—gemological terms referring to the sparkle and color play seen when the diamond, observer, or light source moves—are lessened, leading to the cloudy or murky appearance.

But fear not, diamond owners! This effect is not permanent. Proper cleaning can effectively remove the grease and restore the diamond’s natural brilliance and shine. Regular maintenance, careful handling, and occasional professional cleanings can ensure that your diamond continues to shine brilliantly, just as it was meant to.

Diamond Not Properly Cut

Cut is a critical factor that influences a diamond’s overall appearance, including its clarity and brilliance. A diamond that hasn’t been cut properly may indeed appear cloudy or less brilliant. Here’s why:

A diamond’s sparkle and clarity significantly depend on the quality of its cut, which refers to how well the diamond has been shaped and faceted from its rough state. An optimal cut can effectively manipulate light, causing it to bounce within the diamond and reflect back to the viewer’s eye, creating the intense sparkle diamonds are known for.

However, if the diamond is cut poorly – for instance, if the cut is too shallow or too deep – the light entering the diamond can leak out from the sides or the bottom instead of being reflected back. In such a case, the diamond will not refract light effectively, leading to less brilliance and a perceived cloudy appearance.

Moreover, a poor cut can highlight inclusions or internal flaws in the diamond, making them more apparent and thus making the diamond look cloudier. In a well-cut diamond, light refraction can often mask minor inclusions, but when the cut isn’t optimal, these imperfections become more visible.

In the diamond business, the cut grade is so crucial that it can impact the value of a diamond significantly. A diamond with higher cut grade will often be more expensive than a similar diamond with a less cut grade, all other factors (like carat weight, colour, and clarity) being equal. So, a proper cut not only ensures maximum brilliance and sparkle, but it also contributes to a diamond’s overall quality and value.

Lower Clarity Diamond

The clarity of a diamond is one of the four main factors, along with cut, colour, and carat weight (the “Four Cs”), that determine a diamond’s quality and value. Clarity refers to the presence of inner or outer faults, known as inclusions and imperfections, respectively. These imperfections can range from tiny spots, lines, or cracks to larger, more noticeable features.

A diamond with lower clarity has more of these inclusions and blemishes, which can interfere with the passage of light through the diamond, reducing its ability to sparkle and potentially giving it a cloudy appearance.

Here’s why:

In a high-clarity diamond, light can pass through unobstructed, bouncing off the internal facets and reflecting back out to the viewer’s eye, creating a brilliant sparkle. In a lower-clarity diamond, the presence of inclusions can disrupt this path of light. Instead of flowing smoothly through the stone, light might bounce off these inclusions in unpredictable ways, or be absorbed or trapped within them. This results in less light being reflected back to the viewer, making the diamond appear less brilliant and potentially more cloudy or dull.

The size, number, position, and color of these inclusions can influence the degree to which they affect the diamond’s appearance. For example, a large inclusion located directly under the table (the flat top facet of the diamond) will be more noticeable and more likely to impact the overall look of the stone than a small inclusion located near the girdle (the edge of the diamond where the top and bottom, or crown and pavilion, meet).

It’s worth noting, however, that many inclusions are microscopic and do not significantly affect a diamond’s beauty to the naked eye. It’s only when the inclusions are numerous or large enough that they might make the diamond appear cloudy. In such cases, a skilled gemologist might be able to improve the appearance of the diamond by recutting it, although this will also reduce its carat weight.

Ways To Clean Your Diamond To Make It Look Less Cloudy

Restoring a diamond’s sparkle and reducing its cloudy appearance can often be as simple as giving it a good cleaning. Over time, diamonds can accumulate a layer of grime, oils, and other residues that can dull their brilliance. Here are some effective methods to keep your diamond sparkling clean:

Dish Soap and Warm Water:

The simplest and safest method to clean your diamond jewellery is with some mild dish soap and warm water.

Mix a few drops of dish soap into a bowl of warm water.
Place your diamond jewelry in the solution and let it soak for about 20-30 minutes.
After soaking, use a soft toothbrush to gently scrub the diamond and the setting. Be sure to get into the small crevices and underneath the diamond where dirt can accumulate.
Rinse under warm running water and dry with a lint-free cloth or let it air dry.

Jewellery Cleaner Solutions:

There are commercial jewellery cleaner solutions available that can effectively clean diamond jewellery.

Follow the instructions provided with the cleaner. This usually involves soaking the jewellery and then gently brushing it.
Be sure to choose a solution that is safe for any other gemstones or materials in your jewellery.

Ultrasonic Cleaners:

Ultrasonic cleaners use sound waves to create bubbles that help remove stubborn dirt and grime.

Be cautious when using an ultrasonic cleaner; while diamonds themselves are extremely durable, the vibrations can potentially loosen the setting, particularly if it’s already weakened by wear and tear.

Professional Cleaning:

If your diamond jewellery still looks dull after home cleaning, or if it’s particularly valuable or has a delicate setting, consider having it professionally cleaned. Jewellers have specialized tools and knowledge that allow them to clean diamond jewellery thoroughly without damaging it.

In addition to cleaning, they can also check the security of the setting and give the jewellery a high-quality polish.

Please note: Always ensure that your cleaning method is suitable for both the diamond and its setting. Some metals and other gemstones may require special care, and some cleaning methods might not be suitable. If in doubt, consult a professional jeweler.

Regular cleaning can help keep your diamond looking brilliant and reduce the likelihood of it appearing cloudy. A good rule of thumb is to clean your diamond jewellery once every one or two weeks, or more often if it’s exposed to a lot of dirt or grime.

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