Blue Diamonds

Natural fancy coloured diamonds are very rare and expensive. Blue is one of the rarest and most desirable colours. The Hope diamond, which we have viewed in the Smithsonian Institution in Washington D.C., is the most famous blue diamond in the world, and the largest at 45.52 carats.

Blue is a perceived color representing the sky on a clear day. Positioned on the spectrum between violet and green, blue may contain secondary color modifiers such as blackish blue (bk-B), grayish blue (gy-B) and greenish blue (g-B). Alternatively, blue itself may occur as a secondary color modifier as in bluish green (b-G), or bluish gray (b-GY). Popular names for mixtures of blue are: cornflower, indigo, ink, navy, sapphire and sea.

The blue diamonds that you find in your local jewelry store were made by chemists using methods that mimic conditions that existed millions of years ago. First, they irradiate the diamond causing the color to change, next, they give the diamond a heat treatment to stabilize the color. Although most blue diamonds are not natural, they are difficult to make and maintain to be more expensive than colorless diamonds.

Quality for quality, fancy blue diamonds are more expensive than ordinary near-colourless ones. The processing adds to the costs, so it is generally only worth treating diamonds of high clarity. The diamonds selected for treatment usually start off a one of the less desirable colours such as brown or yellow. There is no certainty about the final colour that any particular stone will be after treatment.

There are many other fancy colored diamonds which are far more attractive. Here is the information about other fancy colored diamonds.