The four Cs — and what they actually mean
Carat is weight, not size. Two stones of identical carat weight can look very different depending on how they are cut. Cut quality governs brilliance more than any other factor — a poorly proportioned stone leaks light, while a well-cut stone returns it.
Colour grades run from D (colourless) to Z (light yellow or brown). For most buyers, the meaningful range is D through J; below that, warmth becomes visible to the unaided eye in most settings.
Clarity and fluorescence
Clarity grades describe inclusions and blemishes. FL (Flawless) and IF (Internally Flawless) are rare and command significant premiums; VS1–VS2 stones offer excellent value because inclusions are invisible without magnification.
Fluorescence is often misunderstood. Strong blue fluorescence can make a lower-colour stone appear whiter in daylight — an advantage for some buyers and a distraction for others. Read it as a characteristic, not a defect.
Laboratory credentials
GIA and AGS reports are the industry benchmark. IGI and HRD are credible for lab-grown stones. Be cautious with reports from laboratories outside the recognised tier — grading standards vary materially.
