Diamond knowledge: the four Cs in plain English
Every diamond is graded on cut, carat, colour and clarity. Here is what each one means, and which ones are worth paying for.
Cut: pay for this one
Cut is the angles and proportions of the stone. It decides how much light comes back out of the top, which is what you see as sparkle.
A well-cut stone looks brighter than a bigger stone cut badly. Aim for an Excellent or Very Good cut grade before you spend on anything else.
Carat: weight, not size
Carat is weight. 100 points make one carat, so a quarter-carat stone is 25 points or 0.25ct.
Price jumps at the round numbers. A 0.90ct stone looks almost the same as a 1.00ct stone on the hand and costs noticeably less.
Colour: G to H is the sweet spot
Colour runs from D (no colour) to Z (yellow or brown tint). The less colour, the higher the grade and the price.
Once a stone is set, most people cannot tell G or H from D. That is where the value sits.
Clarity: eye-clean is enough
Clarity grades count the natural marks inside the stone, from Flawless down to Included.
Marks at VS and many SI grades are invisible without a loupe. Choose a stone that is clean to the eye rather than paying for a grade you will never see.
