A feather inclusion is a type of blemish or defect found in a diamond that appears as a white, wispy line or feather-like shape. It is caused by a crack or break in the diamond structure, which can weaken the overall durability of the stone.
If larger or located in a prominent area, it might also affect the diamond's appearance. To identify a problematic feather, look for jagged or irregular shapes and assess its location and size.
A crystal inclusion refers to a foreign mineral or diamond crystal that is trapped within the diamond's structure.
To identify if this is a significant issue, it is crucial to consider the size, location, and color of the crystal. If a crystal is located at the center of the diamond or near the table, it may be more visible and affect the diamond's pattern of light return. If the crystal is dark or colored, it can be more noticeable against the background of a colorless diamond.
A cloud inclusion refers to a group of tiny, hazy or milky inclusions in a diamond that appear together to form a cloud-like appearance.
Small clouds are usually not a problem, but if the clouds are large and dense, they can affect the transparency and brilliance of the diamond.
Specifically, if this diamond is SI1 or SI2 clarity and the report comments indicate "clarity grade based on clouds not shown" then we'd recommend you avoid this diamond.
A twinning wisp inclusion refers to a pattern of parallel lines or curved shapes in a diamond that are the result of twinning in the crystal structure.
They can impact a diamond's transparency if they are numerous or dense, creating a hazy appearance. To assess the impact of twinning wisps, closely examine the diamond under magnification for any patterns and evaluate their density and overall effect on clarity.
A needle inclusion refers to a long, slender and often shiny inclusion in a diamond that has a needle-like appearance.
A single needle or a few isolated needles in a diamond are typically not problematic. However, clusters of needles or very large, dark, or centrally located needles could potentially pose issues.
Here's why:
- If needles are large, dark, or centrally located, they can be visible to the naked eye and detract from the beauty of the diamond.
- Needles can disrupt the path of light traveling within a diamond. If there are many needles or if they're located in key areas, they can reduce the diamond's brilliance.
A cavity inclusion refers to a large, open inclusion in a diamond that appears as an empty space or hole. It is usually caused by a previous break or damage to the diamond and can negatively impact the clarity of the stone.
A problematic cavity may lead to discoloration or visible irregularities, so inspect the diamond for any noticeable cavities and their depth.
An Indented Natural inclusion refers to a small, flat surface or dimple in a diamond that has not been polished. It is created during the diamond's formation process and can negatively impact the clarity of the diamond. The visibility and impact of Indented Naturals depend on their size, location, and number within the diamond. They are considered a type of blemish or defect and can affect a diamond's value.
If the indented natural is located near the girdle and is minimal in size, it may not affect the brilliance or face-up appearance but could cause durability issues. A larger or deeper indented natural might pose more significant problems.
A knot inclusion refers to a diamond crystal that is included at the surface of the diamond and is not completely polished. It appears as a small, rounded bump on the surface of the diamond and can negatively impact the clarity of the stone.
To identify a problematic knot, look for raised areas or planar shapes and analyze their location and size.
A small hole created to improve clarity by removing an inclusion. If not done responsibly, it can lead to durability concerns or reduce the diamond's value. To inspect a laser drill hole, verify that it was done properly without causing any noticeable structural weakness.
A natural inclusion refers to a blemish or defect found in a diamond that was created during the diamond's formation process. They can include things such as cracks, mineral deposits, or other crystals. Naturals can negatively impact the clarity of the diamond and their visibility depends on their size, location, and number within the diamond. Natural inclusions can affect a diamond's value and are not to be confused with "Indented Naturals."
A small shallow indentation or notch on the diamond's surface that may compromise its appearance and also potentially affect durability. Check the diamond carefully for any visible chips or evidence of damage and evaluate their impact on the diamond's overall appearance.
An etch channel is a tiny channel created by a laser, typically employed to remove a surface-reaching inclusion.
To determine whether an etch channel is problematic, inspect the diamond for any visible channels or discoloration and assess their overall impact on the stone's integrity.
A bruise inclusion refers to a diamond that has a dark or discolored area within the crystal structure, caused by internal pressure or impact. Bruises can negatively impact a diamond's clarity and their visibility depends on their size, location, and number within the diamond. Bruises are considered a type of blemish or defect and can affect a diamond's value.
A tiny crystal within the diamond that does not usually affect appearance as it is not visible to the naked eye. Pinpoint inclusions are small, but they can be numerous and collectively have a noticeable impact on the diamond's appearance.
If numerous or clustered, they might create a hazy appearance. Examine the diamond under magnification to identify any problematic pinpoint inclusions.
This term refers to traces or characteristics within a lab-grown diamond that are remnants from its creation process. These can include metallic inclusions or distinctive growth patterns, which are not typically found in natural diamonds.
Growth remnants typically resemble crystals, clouds or twinning wisps.
As with any diamond (natural or lab grown) if the clarity is VS2 or higher then the growth remnant likely won't impact the diamond's brilliance. If SI1 or SI2 clarity then we'd recommend inspecting carefully to determine if the growth remnant is visible to the naked eye.
This type of graining can be seen inside the diamond. It can look like faint lines, curves, or streaks, or it can give parts of the diamond a slightly milky appearance.
Internal graining can sometimes affect a diamond's clarity grade depending on its visibility and the extent of the graining.
This appears on the surface of a diamond and can look like small, irregular grooves or ridges on the diamond's surface.
Surface graining does not usually affect the diamond's clarity grade unless it is severe or extensive. Instead, it might be factored into the diamond's polish grade.
Inclusions are one of the key factors that determine a diamond's clarity, which is one of the Four Cs (Carat, Color, Clarity, and Cut) used to evaluate and price a diamond.
How sparkly will your diamond look in person? Our cut score uses each diamond’s unique dimensions to determine just how perfectly it’s cut (and how well it will reflect light).
Cut scores range from 0 (worst) to 10 (best). A cut score of 9.0 or higher is in the top 25% of all GIA Excellent Cut graded diamonds.
StoneAlgo typically recommends looking for round diamonds with a cut score of 7.0 or better.
Like a Zillow Zestimate for your diamond. Our Fair Price Estimate is updated daily based on live diamond prices from top online jewelers. This is not an offer to buy or sell this diamond.
Please keep in mind that every diamond is unique and some real-life diamond prices will differ meaningfully from our fair price estimate.
Based on analysis of similar diamonds, the fair price we'd expect to see this diamond sold for is $2,221.
Based on live market data, the range you would expect to see for this fair price estimate is $1,567 - $3,203.
This is the price range you would expect to see for diamonds like this one. Our estimate range takes into account today's prices from the top online jewelers.
Keep in mind that the more data we have for a given diamond category the better the estimate range will be. So, for more rare requests (e.g. 4 Carat Marquise K IF diamonds) the range may be very wide.
Like a Zillow Zestimate for your diamond. Our Fair Price Estimate is updated daily based on live diamond prices from top online jewelers. Please keep in mind that every diamond is unique and some real-life diamond prices will differ meaningfully from our fair price estimate.
StoneAlgo developed our Visual Carat metric to help you understand whether your diamond looks larger or smaller than its actual carat weight implies.
For example, a 1 carat diamond could have a Visual Carat of 1.05 (meaning it looks like your average 1.05 carat diamond) or a smaller Visual Carat like 0.95 (meaning it looks like a 0.95 carat diamond when viewed from above).
This diamond looks 0.09 carats smaller than its actual weight.
Length-to-width ratio is calculated by dividing the widest part of the diamond by the narrowest part. A length-to-width ratio of 1.00 would be a perfect circle or square. As the ratio rises above 1 the diamond will begin to look more oval or rectangular.
For Marquise diamonds it really comes down to a matter of preference. This diamond's ratio is 1.94.
Lab Grown diamonds, also known as man-made diamonds or simply “lab diamonds”, are grown in a highly controlled environment that seeks to replicate the growing process that occurred in nature billions of years ago to create "natural" diamonds.
Lab grown diamonds have a number of benefits which you can read about here.
Our partners at BriteCo offer very competitive insurance pricing. Check them out here.
Get an email alert directly to your inbox when the price of this diamond changes.
We will never send more than one email per day.
GIA stands for Gemological Institute of America. They're like diamond detectives who make sure your diamond is real and high-quality!
AGS is short for American Gem Society. They're a group of experts who check your diamond and give it a special grade.
IGI means International Gemological Institute. They're from all over the world and help figure out how good your diamond is.
Girdle thickness is how thick the diamond's belt is. A good thickness helps make the diamond strong and pretty.
Concerns are potential issues we’ve spotted based on your diamond’s grading certificate. For example, certain inclusion types (such as cavities) are best avoided.
See more details on each concern in our interactive certificate section below.
Symmetry is how well the diamond's shape is balanced. If it's really symmetrical, it will sparkle more! We recommend very good or excellent symmetry.
Polish is how smooth the diamond's surface is. A well-polished diamond will be extra shiny and bright. We recommend very good or excellent polish.
This refers to a diamond's ability to emit light when exposed to ultraviolet (UV) rays. While most diamonds exhibit no fluorescence, some can glow blue, yellow, or other colors under UV light. In most cases, fluorescence isn't visible under normal lighting conditions and doesn't impact a diamond's appearance. However, strong fluorescence can sometimes make a diamond appear hazy or oily in sunlight.
These refer to the internal (inclusions) and external (blemishes) imperfections present in a diamond. Inclusions can be things like crystals or feathers, while blemishes include scratches or pits on the diamond's surface.
Clarity grading ranges from Flawless (no inclusions or blemishes visible under 10x magnification) to Included (inclusions and/or blemishes visible to the naked eye). While no diamond is perfectly pure, the ones closer to Flawless are the most sought after. However, many inclusions and blemishes can't be seen by the naked eye, meaning a lower clarity grade could be a cost-effective choice that still looks perfect without magnification.
These are microscopic markings laser etched onto the girdle of a diamond. Inscriptions often include the diamond's unique identification number which matches the grading report issued by a gemological laboratory (such as the GIA). This number provides an added level of security, and allows you to verify the diamond's grading information. Some diamonds may also have a brand logo or other unique symbol inscribed. Inscriptions are usually not visible to the naked eye but can be seen under magnification.
This section of a diamond grading report provides additional important information that doesn't fit into the standard categories on the report. It might include details about characteristics that are unique to the diamond, such as any noticeable inclusions, extra facets, or workmanship of the cut. It can also note if the diamond has been treated to improve its color or clarity. These comments provide more context to help you understand the diamond's overall quality and appearance.
Cut Grade represents the quality of a diamond's proportions, symmetry, and polish, which determine its ability to reflect light, graded from Excellent (or Ideal) to Poor. StoneAlgo calculates our own measure known as “Cut Score” to give a more specific assessment of cut quality.
Note that grading agencies do not provide cut grades for any fancy shape diamonds (e.g. Marquise).
Clarity Grade describes the presence of internal or external flaws, known as inclusions or blemishes respectively, with a scale ranging from Flawless (no inclusions or blemishes visible under 10x magnification) to Included (inclusions and/or blemishes visible to the naked eye).
Color Grade describes how much color is present in a diamond. Perfectly colorless diamond (D color) are extremely rare and expensive. The color grading scale is subdivided into five subcategories, which are: colorless (D-F); near colorless (G-J); faint (K-M); very light (N-R); and light (S-Z).
Carat Weight refers to the physical weight of the diamond, with one carat equivalent to 200 milligrams.
This the date the certificate for this diamond was created. When a diamond undergoes certification all the aspects of the diamond are analyzed and reported on the certificate.
The unique identifier for this diamond. You can use this number to look up any diamond on StoneAlgo. Sometimes, the number is also laser inscribed onto the diamond's girdle for verification.
The high level category for the look of a diamond. Within most shapes there is some variation, e.g. different length to width ratios or cuts that make the appearance even more unique.
Measurements are how big the diamond is in every direction (length, width, and depth). The proper balancing of these dimensions determines how a diamond will look to the human eye.
Table percentage is the size of the diamond's flat top part compared to its width. A well-proportioned table helps the diamond catch light and sparkle.
Depth percentage is how tall the diamond is compared to its width. A good depth percentage makes the diamond look bigger and enhances its sparkle.
Crown angle is the angle between the top flat part and the sides of the diamond. A nice angle helps the diamond shine bright.
Crown height is how tall the top part of the diamond is, above the girdle. A nicely balanced crown height helps the diamond shine brighter and look more beautiful.
Pavilion angle is the angle between the bottom part of the diamond and its sides. A well-chosen pavilion angle helps the diamond reflect light and create a stunning sparkle.
Pavilion depth is how deep the bottom part of the diamond is, below the girdle. A good pavilion depth helps the diamond capture and reflect light for a brilliant appearance.
The "girdle" is like the diamond's belt that separates the crown from the pavilion. When provided in percentage format it is calculated by dividing the girdle thickness in milimeters by the diamond's diameter.
Put simply, it's best if it's not too big or too small, around 2.5%-5.5%
Very thin girdles can make the stone more vulnerable to abrasion and chipping.
The lower half length is expressed as a percentage of the total depth of the diamond. GIA measures the length of the lower half facets from the girdle to their junction with the pavilion main facets. The lower half length can impact the appearance of the diamond's fire and scintillation.
Star length is expressed as a percentage of the total width of the diamond from one edge of the girdle to the opposite edge through the center.
The star facets play an important role in the dispersion of light and the overall brilliance of the diamond. A typical range for star length might be between 45% and 55%, but the optimal length can depend on other proportions and characteristics of the diamond.
The culet of a diamond refers to the tiny point at the bottom of the stone.
Ideally, a diamond's culet is either very small or graded as 'none' or 'pointed,' meaning it's not noticeable and doesn't impact the passage of light through the diamond, allowing for maximum brilliance and sparkle.
The clarity of this diamond is graded as VS1. Inclusions and blemishes are visible under 10x magnification, and in some cases, they may be visible to the naked eye, especially in larger diamonds. We recommend avoiding this diamond unless you are able to fully exmaine it in person to ensure the inclusions are not visible.
The majority of diamonds with a clarity rating of SI2 or worse are not eye clean. This means you'll likely be able to see inclusions with the naked eye when viewing the diamond in person.
Diamonds can be treated in several ways to enhance their color. These processes are designed to improve the diamond's color, making it look closer to a colorless diamond.
Color-treated diamonds are typically less expensive than their naturally colored counterparts. If you are comfortable with the treatment then you may find a good deal!
The most important thing with color treated diamonds is simply that you are aware of it. Certain types of color treatments require special care when it comes to maintenance. You may also want to consider how the treatment could impact the diamond's resale value.
Lastly, treatments such as 'coatings' can wear off or get scratched over time, altering the appearance of the diamond. This may be a concern if you are looking for a diamond that will be worn every day.
For color grades D, E, and F (colorless), a high fluorescence grade (e.g. Medium, Strong or Very Strong) can cause the diamond to look hazy.
Our recommendation is to avoid diamonds with fluorescence grades of Medium or higher for color grades D, E, and F. For color grades G, H, I, and J (near colorless), fluorescence can actually help the diamond look whiter and brighter. For these color grades, we recommend fluorescence grades of Medium or lower.
If you are able to see this diamond in person, we recommend viewing it in natural light and side by side with a diamond that has no fluorescence to see if you can notice any difference.
Diamonds work by refracting light that enters them, splitting this light into its constituent colors, and then reflecting it back out in a way that produces sparkle (also known as "fire") and brightness (also known as "brilliance"). The facets of the diamond, which should be symmetrically aligned, act like tiny mirrors to reflect this light.
If the symmetry is poor, fair or good, the light can get lost or leaked out of the diamond instead of being reflected back to the observer, reducing the diamond's brilliance.
Only about 3.6% of all diamonds we've processed have poor, fair or good symmetry (the rest have very good or excellent).
Like symmetry, the polish quality can affect a diamond's light performance. Surface defects may disrupt light as it passes through the diamond, diminishing the stone's brilliance and fire. This effect is usually only noticeable under magnification and for diamonds with "fair" or "poor" polish grades.
Only about 0.56% of all diamonds we've processed have poor, fair or good polish (the rest have very good or excellent).
The "bowtie effect" refers to a dark area in the shape of a bowtie that can appear in some fancy-cut (non-round) diamonds, such as marquise, oval, and pear shapes. It results from uneven light distribution when the diamond is cut with imperfect facet angles or proportions. This effect is named for its resemblance to a bowtie.
It's important to note that some level of bowtie effect is common in certain fancy shapes, and the presence of a bowtie alone is not necessarily a deal-breaker. It's the prominence of the bowtie that matters. A slight bowtie effect can often be diminished or even disappear entirely as the diamond is moved and viewed from different angles. However, a pronounced, dark bowtie that persists from all viewing angles can significantly detract from a diamond's beauty.
If you're considering a fancy-shaped diamond, it's best to view it in multiple lighting conditions and from various angles to ensure any bowtie effect isn't overly distracting.
Cut has the most significant impact on a diamond's sparkle and brilliance. A well-cut diamond will reflect light beautifully, giving you that desirable sparkle. In contrast, a poorly cut diamond will leak light, making it look dull and lifeless.
A great cut score can compensate for less-than-perfect grades in other areas. In contrast, even a diamond with perfect color and clarity can appear dull if the cut score is low. A high-quality cut is what truly brings a diamond to life.
In a small number of diamonds, strong or very strong fluorescence can cause the diamond to appear hazy or oily in daylight or under fluorescent lighting, which can negatively impact the diamond's brilliance.
If you're considering a diamond with strong fluorescence, I would recommend viewing it in different lighting conditions to ensure the fluorescence doesn't negatively impact its appearance.
Jeweler GPT is a brand new feature from StoneAlgo Labs. It is still in the experimental phase as we roll it out more widely.
We appreciate all the feedback you are willing to provide as iterate to make this product better!
While the IGI (International Gemological Institute) provides a reliable grading for lab grown diamonds, they do not typically provide an explicit list of inclusions. To ensure complete transparency and satisfaction with your diamond purchase we are highlighting this concern so you consider additional resources (like images and videos) while evaluating.
We would highly recommend going with a VS2 or better clarity diamond (especially when shopping for lab grown diamonds!). This will ensure that the diamond is eye-clean and you won't be able to see any inclusions with the naked eye.
Design a one-of-a-kind setting tailored specifically for this diamond, right here on StoneAlgo.
IGI ID LG510191673
Lab Grown 💎Available from Adiamor
4.90 out of 5 stars
$3,246 USD
-
-
$2,221
-
-
1.94
-
-
3.93 ct.
-
-
0
- Shape
-
Marquise
- Carat
-
4.02 ct.
- Color
-
F
- Clarity
-
VS1
-
-
$2,221
-
-
1.94
-
-
3.93 ct.
-
-
0
- Shape
-
Marquise
- Carat
-
4.02 ct.
- Color
-
F
- Clarity
-
VS1
- Fluorescence
-
None
- Symmetry
-
Excellent
- Polish
-
Excellent
- Cert. Lab
-
IGI
Why Adiamor?
Learn more about Adiamor (4.90/5 rating with 379 reviews) and their business including their free, insured shipping and other top quality services.
$2,221
Fair Price Estimate
Like a Zillow Zestimate for your diamond. Based on analysis of similar diamonds, the expected fair price for this diamond is $2,221 with an estimate range of $1,567 - $3,203.
1.94
Length to Width Ratio
Length to width ratio is calculated by dividing the widest part of the diamond by the narrowest part. For Marquise diamonds it really comes down to a matter of preference.
3.93
Visual Carat
Diamonds can look larger or smaller than their actual carat weight when viewed from above. This diamond looks 0.09 carats smaller than its actual weight.
Over the past year, the market price of 4.02 carat marquise lab grown diamonds has ranged from a low of $1,935 to a high of $2,600. Currently the average price point for these diamonds is $2,191 and has decreased 4.03% in the last month.
Here are our top picks based on your diamond. Click results for more details.
(☝️ this is your diamond - See At Adiamor)
Here are some diamonds you've recently viewed on StoneAlgo.
© 2025 StoneAlgo, Inc. All rights reserved.