Our Essential Guide to Buying Diamonds
- Jul 31, 2025
- 7 min read
Updated: Aug 16, 2025
An educational guide for anyone looking to make an informed diamond purchase, no prior knowledge required.
Buying a diamond can feel like navigating a vast, sparkling sea full of unfamiliar terms and countless choices. Whether you seek an engagement ring to mark a promise, a gift to treasure, or a piece just for yourself, this guide is here to light your path, helping you make a confident and informed decision.
Together, we will explore the many shapes diamonds take and guide you through the essentials of evaluating them using the trusted system developed by the Gemological Institute of America (GIA), known as the 4Cs: Colour, Clarity, Cut, and Carat. We will also take a closer look at fluorescence, a subtle detail that’s often overlooked but worth understanding for anyone looking to make an informed choice.
At Huen’s Diamond, we believe transparency and education are the foundation of trust. That’s why we share everything you need to know, not only about the quality of our carefully chosen diamonds but also about the full spectrum of possibilities the market offers.
Shape: First Impressions Matter
One of the first things to catch the eye when gazing at diamonds is its shape, the most visible stylistic signature that speaks to personal taste before any grading criteria come into play.
Round Brilliant Diamonds
The round brilliant cut is the most iconic shape, prized for its symmetry and enduring brilliance. With 58 meticulously crafted facets, round diamonds are designed to maximise light performance. This high level of precision, along with greater material loss during cutting, makes round diamonds costlier in both labour and resources.
Fancy-Shaped Diamonds
They include shapes beyond the classic round, such as Cushion-Cut, Emerald-Cut, Heart-Shape, Marquise, Oval-Shape, Pear-Shape, Princess-Cut, Asscher-Cut, Radiant-Cut, and many more. The beauty of fancy shapes could be found in their balance, where symmetry and proportion are harder to perfect, yet making a significant difference.
Once you’ve found a shape that speaks to you, we can explore the essentials of evaluating them.
Colour: The More Colourless, The Greater Rarity and Value
A diamond’s colour refers to how colourless it appears. The more colourless its appearance, the rarer and more valuable it is. Graded by the GIA from D to Z, the scale begins with diamonds that are colourless and gently moves toward diamonds touched by soft tints of yellow or brown. GIA will carefully examine each diamond against master stones, a series of reference diamonds at each grade, under controlled lighting to ensure every grade is a true reflection of its natural colour state.
Understanding Colour Grades
D: Absolutely colourless. The perfect grade in nature’s palette.
E–F: Colourless to the naked eye, with only the faintest whispers of tint visible to gemologists. These diamonds strike an excellent balance between colour quality and value.
G–J: Near colourless, with soft hints that may gently emerge beside higher grades. Still, they captivate, especially when paired with a strong cut or thoughtful setting.
K–Z: Tints grow more visible here, ranging from subtle to pronounced.
Diamonds that carry colour beyond the Z grade enter the realm of Fancy Colour Diamonds (e.g., pink, yellow, or blue). Graded by their own standards, these vibrant diamonds captivate with their striking appeal and are often treasured for their extraordinary rarity.
Here At Huen’s Diamond,
We stock D to F colour grades to ensure the colourless appearance we expect of our diamonds. We are also able to source diamonds across the grades upon request.
Clarity: The Presence or Absence of Flaws
Clarity reveals how free a diamond is from natural “birthmarks”, known as inclusions within the stone and blemishes on its surface. These features are a result of the diamond's formation deep within the earth. The fewer these characteristics, the rarer and more valuable the diamond is, with flawless stones ranking among the most prized.
GIA evaluates each diamond under 10x magnification and grades clarity on the following scale:
FL (Flawless): No inclusions or blemishes are visible under 10x magnification. Pure and rare.
IF (Internally Flawless): No visible inclusions; only the faintest surface blemishes visible under 10x magnification. Near-perfect and rare.
VVS1 & VVS2 (Very, Very Slightly Included): Minor inclusions that are extremely difficult to detect, even for experienced graders under 10x magnification.
VS1 & VS2 (Very Slightly Included): Minor inclusions that are only visible under 10x magnification and are difficult to see with the naked eye. These diamonds strike an excellent balance between clarity and value.
Slightly Included (SI1, SI2): Inclusions are noticeable under 10x magnification and may occasionally be visible to the naked eye. Offers affordability with minimal impact on overall appearance.
Included (I1, I2, I3): Inclusions are easily visible under 10x magnification and often noticeable to the naked eye. These diamonds have unique characters and are an accessible option for budget-conscious buyers.
Here At Huen’s Diamond,
We stock diamonds with clarity grades of FL, IF, VVS1, VVS2, VS1, and VS2, with our VVS and VS graded diamonds lacking black inclusions to ensure a clean visual appearance. We are also able to source diamonds of other clarity grades upon request.
Cut: The Sparkle Factor
Cut is often confused with shape, but it actually refers to a diamond’s proportion, symmetry, and polish. It is the secret behind a diamond’s dance with light, how it captures, bends, and reflects every ray to reveal its sparkle. A masterfully cut diamond has the ability to maximise its light performance, defined by 3 aspects:
Brilliance: The intensity of white light reflected from the diamond’s surface and internal facets.
Fire: A playful burst of vibrant colours like red, blue, and green that dance and shimmer as light breaks apart within the diamond.
Scintillation: The lively sparkle that flickers and shifts in a pattern of light and dark areas when a diamond moves.
GIA evaluates each diamond's cutting based on its Cut, Polish and Symmetry, and grades them as Excellent, Very Good, Good, Fair, and Poor. An “Excellent” cut diamond possesses well-balanced proportions, perfect symmetry, and a high-quality polish for superior light performance, while a diamond of a lower cut grade may let light slip away, diminishing its sparkle visually.
Cut Grade: Only applicable to round diamonds. GIA does not assign an overall cut grade for fancy-shaped diamonds as their light performance varies significantly by shape.
Polish: The smoothness of a diamond's surface, affecting how light can glide through. A high-quality polish will allow light to pass through undisturbed, which enhances a diamond's brilliance.
Symmetry: The alignment of a diamond's facets, affecting how evenly light is reflected. An excellent symmetry ensures light is evenly reflected, contributing to an optimal sparkle and visual balance.
Here At Huen’s Diamond,
All our round diamonds are Triple Excellent, meaning they receive the highest possible grade in Cut, Polish, and Symmetry. For fancy-shaped diamonds, we only select those with Excellent or Very Good grades to ensure excellent light performance and aesthetic balance despite their complex geometry.
Carat: A Diamond’s Weight
Many people mistakenly associate carat with a diamond’s size. However, it refers to a diamond’s weight, with one carat equalling 200 milligrams (0.2 grams), and it can be divided into 100 points. Hence, diamonds weighing less than one carat are referred to in points (e.g., a 0.10 carat diamond = 10 points).
What many don’t realise is that carat weight doesn’t always correlate with how big a diamond looks. Two diamonds may carry the same weight, yet one may seem smaller, shaped by its cut.
For instance, a deep-cut 1.2-carat diamond may appear more modest than a well-cut 1.0-carat diamond, as much of its weight hides beneath the surface. This is why other factors, like Cut, are important alongside weight.
As prices leap at various carat milestones (e.g., 1.00, 1.50, 2.0 ct), choosing a premium size, such as a 0.99ct / 1.99ct, that is just shy of a full carat weight offers nearly the same presence for a gentler price.
Here At Huen’s Diamond,
We stock only diamonds of 0.30 carats and above, most of which are GIA graded. We are here to help you find the right balance between size, quality, and value based on your preferences and priorities so you can make a decision that aligns with your goals.
Fluorescence: The Diamond’s Hidden Glow
Fluorescence is a diamond’s natural response to ultraviolet (UV) light, found in about one in every four stones. It is often seen as a soft blue glow, but it can also present itself with hints of other colours.
This is a natural phenomenon born from small amounts of impurities, like trapped nitrogen during a diamond’s natural formation, or a structural quirk in the arrangement of its carbon atoms.
While GIA grades fluorescence as None, Faint, Medium, Strong, or Very Strong, whether it enchants or distracts is a matter of personal preference.
What Does It Mean for You?
In diamonds with lower-colour grades (like grades I to M), fluorescence can enhance the diamond’s appearance, softening yellow tints and lending a whiter appearance in daylight’s embrace.
However, in higher-colour diamonds (D to F), the fluorescence may cast a gentle haze, which some prefer to avoid in their quest for flawless colour.
Here At Huen’s Diamond,
We only stock diamonds graded with “None” fluorescence to ensure our D–F colour diamonds maintain their colourless appearance under all lighting conditions.
However, if you’re interested in fluorescence or exploring options in the faintly tinted ranges, we’re happy to help you evaluate whether a diamond with fluorescence might offer value or visual appeal.
In Summary
At Huen’s Diamond, every diamond we offer is 100% natural and carefully chosen to meet our high-quality standards. This promise is woven into our collections, reflecting the quality you can expect:
Colour: D to F
Clarity: FL, IF, VVS1, VVS2, VS1, and VS2
Cut: Triple Excellent for round. Excellent/Very Good Polish and Symmetry for Fancy Shapes.
Carat: 0.30-carat and above, comes with GIA certificate.
Fluorescence: None
While our collection reflects these high standards, we are also happy to source diamonds tailored to your preferences upon request.
We practice transparent pricing, guided by a globally recognised diamond pricing chart, to ensure fair prices free from inflated markups or brand premiums.
If you are beginning your journey into the world of diamonds, let us walk beside you, offering unbiased guidance and explaining any potential trade-offs, so you can make an informed and assured decision.