Diamonds: The Four C’s
The diamond color scale extends from D (colorless) to Z (light yellow or brown).
Although many people think of gem quality diamonds as colorless, truly colorless diamonds are actually quite rare. Most diamonds used in jewelry are nearly colorless with tints of yellow or brown.
Fluorescence – Some diamonds can emit a visible light when exposed to ultraviolet radiation, but fluorescence is not a factor in determining color or clarity grades.
The diamond clarity scale ranges from Flawless to I3. A diamond’s “clarity” is its relative position on a flawless to imperfect scale. A diamond’s clarity is determined by its internal features, called inclusions, and its external features, termed blemishes. These irregularities or characteristics are a by-product of a diamond’s natural formation under heat and pressure within the earth.
FLAWLESS to INTERNLLY FLAWLESS – FL, IF
No inclusions visible under 10x magnification.
VERY VERY SLIGHTLY INCLUDED – VVS1, VVS2
Inclusions are minute and extremely difficult to locate under 10x magnification
VERY SLIGHTLY INCLUDED – VS1, VS2
Inclusions are minor and difficult to locate under 10x magnifiction, and never visible to the naked eye
SLIGHTLY INCLUDED – SI1, SI2
Inclusions are noticeable and relatively easy to locate under 10x magnification, but should not be visible to the naked eye
INCLUDED – I1, I2, I3
Inclusions are obvious under 10x magnification and are visible to the naked eye
A polished diamond’s cut or make is based on its proportions, symmetry, and polish. Each of these variables affects how light hits a diamond and in return, how that light hits your eyes. There are three important attributes to consider when determining cut.
Brilliance – the combination of all white light reflecting from the surface and interior of a diamond
Fire or Dispersion – the separation of white light into spectral hues and the “rainbow” colors emitted from a diamond
Scintillation – the flashes of light, or sparkle, you see when a diamond moves
One carat equals 200 milligrams in weight. For diamonds under one carat, each carat is divided into 100 points.
0.75 ct = 75 points
1/2 ct = 50 points
GIA.edu. 15 Feb. 2008. Gemological Institute of America.