The 4Cs — Cut, Colour, Clarity, Carat — were introduced by GIA in the 1950s to give buyers a common language. They were revolutionary at the time. But the diamond industry has moved forward since then, and the 4Cs alone no longer tell the full story of what makes a diamond worth buying.
At GV Diamonds, we teach 7Cs. The three we add are not marketing invention — they are the factors that our clients consistently tell us mattered most once they actually held the stone in their hands.
The Original Four
Cut is the most critical of the 4Cs. It determines how the stone interacts with light — whether it returns light to your eye (brilliance), disperses it into spectral colour (fire), or scintillates as it moves. A poorly cut stone with excellent colour and clarity will look dull. A well-cut stone with modest grades will look alive. If you are choosing where to spend, spend on cut.
Colour runs from D (colourless) to Z (noticeably yellow). The sweet spot for most buyers is F–H: the stone reads colourless to the naked eye, but without the premium of D–E grades that require laboratory conditions to appreciate.
Clarity measures inclusions (internal) and blemishes (external). FL (flawless) is extremely rare. VS1/VS2 is our recommended range — the inclusions are not visible without magnification, which means the stone looks clean in real life while avoiding the premium of IF or FL grades.
Carat is weight, not size. A well-cut 0.90ct can face up larger than a poorly cut 1.10ct. Understanding this reframes carat-chasing into something more useful: cut-literacy.
The Three We Add
Certification is the most underweighted factor in most buying guides. Not all labs grade the same way. GIA is the global standard. IGI has improved significantly and is widely accepted. HRD is rigorous for European buyers. The lab matters — not because one lab's diamond is "better", but because a G/VS1 from GIA and a G/VS1 from a lesser lab may not be the same stone. GV Diamonds uses dual certification (GIA + IGI) for precisely this reason.
Contour (Shape) is what most people call "shape" — Round, Oval, Cushion, Pear, Marquise, Emerald, Radiant, Asscher, Princess, Heart. Shape affects apparent size, price per carat (rounds command a premium), and light performance. Fancy shapes often offer better value per carat than rounds at equivalent grades.
Cost — specifically, what drives it. Understanding that diamond pricing is driven by the sourcing chain (not just the 4Cs) is what lets you buy intelligently. Wholesale price + cutter margin + retailer markup + showroom overhead is the typical chain. GV Diamonds removes the last two steps. Knowing this lets you ask the right questions of any seller.