The 4Cs explained clearly.

The 4Cs are four English terms the whole industry uses to describe a diamond's quality: Cut, Color, Clarity, Carat. Sounds like technical jargon, but it's understood in a quarter of an hour. That's exactly what we'll do here.

Let's start with the cut, because it's the most important of the four. The cut decides how a diamond throws light back, in other words whether it sparkles or looks dull. A perfectly cut stone of medium quality shines more than a poorly cut top-grade one. This is where you should never save.

Color is given in letters from D to Z. D is completely colourless; the further it goes towards Z, the more yellowish the stone becomes. The secret: in the finished ring, hardly anyone sees the difference between a D and a G. A grade like F or G gives you a white sparkle without paying for invisible perfection.

Clarity describes the tiny inclusions in the stone that formed as it came into being. The scale runs from flawless to clearly visible. Here too: much of it is only visible under tenfold magnification. A grade like VS1 or VS2 is clean to the naked eye and noticeably easier on your budget.

Carat, the weight, is what everyone talks about, and what costs the most. One carat is 0.2 grams. The catch: the price doesn't rise evenly, it jumps up at round marks like 1.0 carat. A stone of 0.9 carat looks almost the same size but costs noticeably less.

Now the most important thing, which no shop window tells you: the four Cs work together. Whoever spends the money wisely buys a good cut, a colour and clarity just below the top, and a weight just below the next round mark. That way you get a stone that looks magnificent on the finger without paying for numbers that only shine on paper.

And that's exactly our job: to show you where it's worth looking closely, and where you can save with peace of mind. What's on the paper is checked by an independent laboratory, IGI or GIA. What suits your finger we figure out together – no jargon, no show.