A grading report is a language. Here is the vocabulary.
Cut, colour, clarity and carat are not marketing words — they are the four measurements a laboratory takes so that two strangers can agree on what a stone is. Below is what each one means, counted against the 26 certified stones we are holding today. Every grade links to the ones we have.
The first CCut
What the cutter did with the rough.
The only C decided by a person rather than by geology, and the one that does most of the work. Cut grades the proportions and finish — how well the stone returns the light you put into it. A superbly cut J will out-sparkle a badly cut D.
The second CColour
Graded on how little of it there is.
The scale runs D to Z, and it measures absence: D is colourless, and by Z there is an obvious warm tint. The steps are subtle — most people cannot pick D from G once a stone is set, which is exactly where the value sits.
The third CClarity
What a loupe finds at ten times.
Diamonds grow with birthmarks. Clarity records what a grader can see at 10× magnification — not what you can see. Below VS the inclusions are still invisible across a table; that gap between what a loupe finds and what an eye finds is where a lot of money is saved.
- FL Flawless — nothing under 10× magnification. 3 stones
- IF Internally flawless — surface marks only. 3 stones
- VVS1 Very, very slight — a grader needs to hunt. 4 stones
- VVS2 Very, very slight — still invisible to you. 4 stones
- VS1 Very slight — hard to spot at 10×. 5 stones
- VS2 Very slight — findable at 10×, not by eye. 4 stones
- SI1 Slight — visible at 10×, usually clean to the eye. 3 stones
The fourth CCarat
Weight, not size.
A carat is a fifth of a gram. It measures mass, so two stones of the same weight can look different sizes depending on how they are cut. Price does not climb in a straight line either — it jumps at the round numbers, which is why 0.90 ct is often the better buy than 1.00 ct.
Certification
The four Cs only mean anything because someone independent measured them. We sell stones graded by two laboratories, and the report number on each one can be checked against the lab's own database — not ours. If a stone has no report, it has no grade; it has an opinion.
GIA
Gemological Institute of America
The institute that invented the 4C scale in the 1950s, and still the strictest reading of it. Expect to pay a little more for the same grades on a GIA report.
IGI
International Gemological Institute
Widely used, and the standard for lab-grown stones. Fast, consistent, and accepted everywhere — which is why most of our lab-grown inventory carries it.
Every diamond we list shows its lab and report number before you buy, and the stone ships with the paper. Lab-grown stones are always labelled as such — never as a footnote.
Now go and use it.
The search takes all four Cs at once — set what matters to you and let the rest move.