COLOR

It's ironic that the very best color for a diamond is no color at all. A totally colorless diamond best allows white light to pass effortlessly through it and be dispersed as rainbows of color. Yes, diamonds come in every color of the rainbow. These are known as "fancies". The most common measure of diamond color comes from the Gemological Institute of America (GIA). The purest, colorless stone carries a "D" rating and this scale goes right through the alphabet to "Z" - designating a strong brown or yellow cast, (the scale starts with "D" because at the time the system was created in the early 1950s, the business was plagued with hucksters offering AA and AAAs - and GIA wanted to distance itself from this hype.) Gradations on the color scale are so precise and so minute that it's almost impossible for an untrained eye to see them. You have to go fairly far down the scale, perhaps to a J or K, before a yellowish tint is noticed.

Color, like the other three C's, has a big impact on price, a "D" diamond costs much more than a "G" which is equal in every other aspect, because it is more rare.

Colorless is ideal for a diamond, but color in a diamond can be a blessing, if it's deep enough and attractive enough to be determined a "fancy", which is also rare.