4Cs of Diamonds
Also called four cs, 4 c's of diamonds
The 4Cs of diamonds are the four factors used to grade a stone: carat weight, cut, color, and clarity. Together they describe how heavy a diamond is, how well it is shaped, how colorless it looks, and how clean it is inside.
In other words, four measures that between them explain what a diamond is and roughly what it should cost, used by every lab and dealer.
What each C measures
The four are not equally weighted. Cut has the biggest effect on how a stone looks in a photo, while carat has the biggest effect on price. Color and clarity mostly decide whether a buyer feels they got a clean stone.
- Carat: the weight of the stone, measured in metric carats.
- Cut: how well the facets are proportioned and finished, graded by GIA from Excellent down to Poor on round brilliants.
- Color: how little body color a white diamond shows, graded D through Z.
- Clarity: how few inclusions and surface marks the stone has, graded Flawless down to I3.
Why it matters for rendering
A render has to agree with the grading on your listing. If the spec sheet says a 1.00 carat G VS1 round, the stone in the image needs to sit at the right size in the head, show no visible inclusions, and read as near colorless against white gold rather than warm.
This is why we ask for stone details along with the CAD file. The geometry tells us where the stone sits. It does not tell us whether the stone is a warm K in yellow gold or a colorless D in platinum, and those two look different on a screen.
What we need from you
Send the 4Cs for the centre stone and the general spec for any side stones. If the piece is sold with several stone options, say so and we will render the version you lead with.
We accept 3DM, STL, OBJ, and STEP files. Stone data can come as a line in the email or a note in the file name. It does not need a formal spec sheet.
Questions about 4Cs of Diamonds
Which of the 4Cs matters most?
Cut, if you care how the stone looks. A well cut stone with a middling color grade usually photographs better than a top color stone that is cut badly. Carat drives price hardest.
Do the 4Cs apply to coloured gemstones?
Only loosely. Sapphires, rubies, and emeralds are graded mainly on color quality and origin, and clarity expectations differ by species. The 4Cs as a fixed scale are a diamond system.
Do you need a grading report to render a stone?
No. A short description is enough: shape, size or carat weight, and roughly where it sits on color and clarity. We only need what changes how the stone should look.