Blue Green Diamonds
Pure blue green diamonds are exceptionally rare and highly valued, ranging in color intensity from faint mint green to vivid emerald green, with varying amounts of secondary blue. Very few natural green diamonds are found each year, making them some of the most collectable of all natural colored diamonds in the world.
Green and blue green diamonds are typically found in South America and Africa. The Dresden Green is probably the most famous of all green diamonds, although more recently The Ocean Paradise diamond and The Ocean Dream diamond have become almost as equally famous. The blue-green color of these two gems has been seen by the GIA on extremely rare occasions. The fancy deep blue-green color of The Ocean Dream diamond may be the only diamond of its kind found to date.
The green to bluish-green color found in these rare diamonds is caused by naturally occurring radiation in proximity of where they form displacing carbon atoms from the crystal structure. The blue tint is a result of their boron content This radiation normally produces red and yellow spectrums, which produce the green to blue-green color in the diamond, dependent upon the elements present in the gem. Irradiation that takes place naturally is certainly the preferred and such stones will command a much higher price than those that are artificially treated after mining.
Many of these diamonds also possess a yellowish or grayish secondary color, reducing their ultimate value. Diamonds possessing pure green or bluish green color command the greatest price due to their scarcity.
As a testament to their rarity, the 1.6 ct Ocean Paradise diamond, discovered in Brazil, is the second natural blue green diamond found, and has been estimated at $2.67 million. The first such gem, the 5.51 ct Ocean Dream diamond, was discovered in Central Africa and is valued at over $10 million. It is also the largest natural fancy deep blue-green diamond yet found. Both these stones are GIA certified to be naturally irradiated.
Bluish green diamonds in the 1.2 carat to 2 carat range can easily fetch $750,000 per carat.
Colored diamonds are graded for color content at several levels of increasing intensity, including: faint, very light, light, fancy light, fancy, fancy intense and fancy vivid. Often, there will be a primary and secondary color grading, such as blue, with some gray. Such mixing of colors typically results in a somewhat lower value being assigned to the diamond.
In the case of blue green diamonds, there are several levels: bluish green, blue green, greenish blue and green blue, based upon which color is most dominant (the latter color cited) and to what degree. Bluish or greenish as a secondary color is not considered to be readily noticeable to the naked eye, whereas blue or green is readily noticeable as a secondary hue.
Purely of one color or the other is relatively rare but generally, all else being equal, a natural intense blue diamond would be more valued than a natural intense green.
Naturally colored diamonds are a result of radiation from surrounding materials over a prolonged period of time. By prolonged, an example would be the Ocean Dream, which is estimated to have been exposed to localized radiation over a period of millions of years.
As with many gemstones, processors attempt to duplicate this process by irradiating stones artificially. While similar aesthetic results can be achieved, the value of such stones is a fraction of natural stones. But because such treatment can dramatically increase a stone’s value, some will try to pass them off as natural stones. Unfortunately, that means that gemologists are naturally skeptical of the authenticity of any blue or green diamonds they encounter. To make matters worse, it can be particularly difficult to determine whether a green diamond is naturally or artificially colored.
Obviously, such beautiful diamonds are unlikely to be applied in an industrial setting. Even small blue green diamonds find their way into jewelry, often clustered with white diamonds or stones of contrasting color. Their rarity alone will largely ensure their high value. The largest aren’t likely to be re-cut, either, at least unless the collective value of the resulting stones far outweighs the intact value.
Some exceptions to that rule can apply, of course. If several highly marketable stones can be cut from a single large gem with an inclusion, thus removing an aspect that decreases the value of the diamond, it might be worthwhile.
But until either that happens or someone discovers a substantial quantity of blue green diamonds, most of us will have to be content with artificially irradiated diamonds or a different hue.