Blue Diamonds

Blue Diamonds are one of nature's greatest rarities. They are considered a great prize in any kind of stone collection. There are more buyers than there are sellers. A top blue diamond can often be priced just like a Renoir or a Picasso painting.

India is the all-time leading producer of large colored diamonds. Indian mines were the source for the blue diamond that became known as the Hope diamond.

Most new blue diamonds today come from South Africa and grey blues tend to come from Australia. The main cause of color in diamonds is the presence of natural irradiation. Blue is caused by the presence of boron.


The new Australian diamonds (argyle) are most likely colored by trait elements of hydrogen or nickel which causes the blue grey color. Small concentrations of boron cause the blue color, and some gray-blues are caused by hydrogen. Colors can vary from a light grayish blue shade to shade similar to steel color-darker than sapphire.

The most famous blue diamond is the Hope diamond. It was sourced from a mine in the Golconda region in India. Originally in 1673 this stone was cut to 67 carat and was sold to King Louis XV of France in 1668. The blue diamond became known as the Blue Diamond of the Crown or the French Blue. It belonged to several generations of French Kings until its disappearance during the French Revolution in 1792. The stone resurfaced in 1830 and was re-cut to disguise it.

The stone come to be known as the Hope diamond from the owner Henry Philip Hope. The diamond developed an association with bad luck when several of its owners came to tragic end such as sudden death or bankruptcy.

In 1988 the Gemological Institute of America observed the diamond has remarkably strong phosphorescence and its clarity possesses a whitish greenish. They grade the color as fancy dark grayish blue.

There simply is not enough production around and blues are truly very rare. No one is holding back on these rough diamonds; it simply does not exist. Prices are escalating and there are so few blue diamonds left is has been impossible to buy them lately.

Since 1992 the market prices have doubles since that time. Many look to auction sales to determine price trends for fancy colored diamonds.

In 1995 at Christy's a 4.37 carat fancy deep blue diamond sold for about 2.4 million dollars or $569,000 per carat. Remember, auctions are not always a good barometer of the market. At times you get two collectors bidding against each other and the final price is unrealistic. This is just an example of how at auction, blue diamond can bring more than $500,000 per carat-one 20 carat stone even sold for over $10 million.

Modifiers of blue diamonds

Beyond pure blue diamonds sometimes have green and gray secondary colors.

Green blue is a very desirable color combination, which often looks like dark aquamarine or the green blue color of the ocean. Grey blue stones are less desirable to a collector, they are substantially less expensive, wonderful for people who want to buy blue without paying the price of the straight blue.

The most desirable colors are fancy intense blue and fancy vivid blue. Most fancy darks are mined in India. Fancy deep blues today are really a more fancy intense grey blue and they are less desirable than straight blues. The final price always depends on the stone itself.
--- Enhanced blues look like natural teal blue diamonds, and are popular because of their low price compared to the real thing.