Learn · Diamonds
Diamond colour, D to Z
GIA's colour scale runs from D, colourless, to Z, light yellow or brown. Move one diamond along it and see it two ways: face-up, as it is worn, and face-down on a white tray, as a grader sees it.
Move along the D-to-Z scale, or choose two grades to compare side by side.
Read the guide
Six-prong solitaire, taken apart
A solitaire ring in 3D: its parts, and how proportions change the cut grade
Diamond clarity map
Every clarity characteristic GIA defines, inside a diamond you can turn
Diamond fluorescence
None to Very Strong under the lamp, and what research found about daylight
Fancy shapes and the bow-tie
Stretch a fancy shape and see where light leaks and the bow-tie appears
Lab-grown, step by step
How CVD and HPHT diamonds are grown, step by step, and how labs tell
How to read a lab report
Each part of a laboratory report explained, on an example report