Diamond Guide: Diamond Types, Cuts And Quality
The ideal diamond is completely colourless. These are the most expensive types of diamond. Though most diamonds appear colourless, they actually have slight tones of yellow or brown. The Gemological Institute of America (GIA), the authority in diamond certification, grades colour alphabetically from D (totally colorless) to Z (heavily tinted).
The difference in grades is very subtle, and mostly not visible to the naked eye. A diamond with a visible tint such as K and above can still be beautiful if it has a good clarity and cut. Only diamonds graded N onwards have a tint that is visible to the naked eye. Beyond S the tint grows more intense. Natural coloured diamonds come in all shades and colours of the rainbow. The most popular colours and diamond types are a combination of pink, blue, brown, yellow, orange, green and red. Yellow is the most common naturally occurring colour in a diamond.
White, red, blue and green diamonds are very rare diamond types.
The cut refers to the proportions, finish, symmetry and polish of the diamonds. These factors determine the intensity and brilliance of a diamond. A well-cut diamond is proportioned, symmetrical, and polished; these are typically the most expensive types of diamond. Well-cut diamonds sell at a premium and poorly cut diamonds sell at discounted prices.
The width and depth of the cut can have an effect on how light travels within the diamond and how it exits in the form of brilliance.