Diamonds explained - A modern guide to old rocks
Author: Nicholas Barker
Buying a diamond is possibly one of the most complex retail conundrums to decipher. I remember the first time Natalia (the boss) explained diamonds to me—I was more confused by the end of the conversation than I had ever been. But years later, the definitions and standards have become second nature, helping me guide clients to find the perfect stone for their taste and budget.
Where Did It All Start?
How did we become a world obsessed with these billion-year-old sparklers?
The first known use of diamonds dates back to the 11th century, when kings and queens were rocking these prestigious sparklers in their crowns. Over time, this royal indulgence trickled down to the elite, gradually increasing the gemstone’s prestige and popularity.
However, the tradition of using diamonds in engagement rings came much later. In 1939, diamond mining giant De Beers launched an advertising campaign with the now-famous slogan "A diamond is forever". The campaign was wildly effective—and by the early 1940s, diamond engagement rings were seriously popping off.
So, What Do You Need to Know?
Certification
A diamond’s certificate confirms its authenticity and outlines all its specifications. Even the most experienced jewellers refer to the certificate first before visually inspecting a stone.
All large diamonds should be certified by recognised bodies such as GIA, IGA, or GCAL.
Image Provided By GIA
Cut
Cut is one of the most important aspects of a diamond’s beauty. A well-cut stone sparkles brilliantly because its facets allow light to bounce through in all the right ways.
Expert lapidaries (stone cutters) work meticulously to maximise this brilliance. After cutting, the diamond’s cut quality is assessed by certifying bodies like GIA, based on symmetry, polish, and proportions.
Colour
Diamond colour is graded on a scale from D (colourless) to Z (light yellow or brown).
D–F (colourless): Highly prized for their rarity and icy appearance
G–J (near colourless): Excellent value with minimal visible tint
K–Z: Increasing presence of yellow/brown tones
When talking about natural diamonds, most clients choose near-colourless stones for their balance of beauty and budget. Lab-grown stones are more accessible price-wise, so colourless stones have become a lot more common.
Clarity
Clarity refers to the presence of inclusions (internal) and blemishes (external). These affect a diamond’s brilliance and transparency.
Grading ranges from:
Flawless (FL) – no imperfections under 10x magnification
Included (I1–I3) – visible inclusions to the naked eye
You don't always need to go for Flawless—many Slightly Included diamonds are eye-clean and offer fantastic value.
Carat
Carat is the unit of weight for diamonds. One carat = 200 milligrams.
Bigger isn’t always better! A slightly smaller diamond with better cut, colour, and clarity can often appear more stunning than a larger one with poor proportions.
Fluorescence
Some diamonds glow under UV light—a trait called fluorescence.
In D-colour diamonds, fluorescence can make the stone appear cloudy or oily, so it's generally best avoided.
In G-or lower colours, a touch of fluorescence can actually help by making the diamond look whiter.
Ethics and Sustainability
More buyers today are asking: "Where did this diamond come from?"
Opting for conflict-free diamonds and supporting ethical and sustainable practices is crucial. Lab-grown diamonds are also growing in popularity, offering an ethical, eco-friendly—and often more affordable—alternative.
Understanding Value
Diamond pricing is influenced by a combination of the 4Cs, market trends, and supply-demand dynamics. Knowing what you're paying for—and why—helps you make confident, informed choices that reflect your priorities.
By grasping these essentials, navigating the diamond world becomes much less daunting. Whether you’re buying for love, for legacy, or just for yourself—you’ll be able to choose a stone that truly sparkles for you.
Thinking about proposing, or simply craving a stunning diamond piece for yourself or a loved one?
Get in touch with Natalia Rafi Jewellery today—we’ll help you find or design the perfect piece that suits your style and budget.
