Well, let’s start with the first of 2 natural ways a diamond gets its blue color from. The first involves the incorporation of the element Boron into the lattice of the diamond replacing atoms of Carbon which classifies them as Type IIb. Boron is the element that manufacturers of semiconductors implant into silicon, allowing them to conduct electricity. Boron has a similar effect on diamonds making them semi conductive.
Let’s take a look at another kind of diamond that may display a distinct blue color as well, the nickel, and hydrogen and nitrogen rich variety of diamond. This type of diamond is pretty much exclusive to the Argyle mine in Northwestern Australia, these types of diamonds typically posses a violet hue. However, when the absorptions responsible for the violet color combine relative to other absorptions intrinsic to a particular diamond, the color may also shift from a pure violet to a straight “blue.
I have had the pleasure of pairing a few of our clients with some pretty spectacular natural blue diamonds in the past. I actually had the pleasure of making one of our dear friends very happy when we delivered this person a GIA certified Natural Fancy Blue, Internally Flawless Diamond just over 3 carats. This was a spectacular Diamond to say the least!
In May 2009, a 7.03-carat Blue diamond fetched the highest price per carat ever paid for a diamond (at the time it was sold) at auction for 10.5 million Swiss francs (6.97 million Euro or US$9.5 million at the time.