The Blue Magic Diamond
Here is what Christies.com's auction said about the stone
when it was up for auction:
"A MAGNIFICENT FANCY VIVID BLUE DIAMOND RING
Set with a modified pear-shaped fancy vivid blue diamond weighing 12.02 carats
to the tapered baguette-cut shoulders and 18k white gold hoop. With certificate
11568233 dated 19 June 2001 from the Gemological Institute of America stating
that the diamond is fancy vivid blue, natural color, VVS2 clarity.
Historically, blue diamonds originated from the Kollur mines
near Golconda in the Indian state of Hyderabad. It is here that historically
important stones such as the Hope Diamond and the Tereschenko were mined. Most
of what is known about early mining activity in India comes through the 17th
century traveler and one of the premier gem-merchants of his time, Jean-Baptiste
Tavernier.
His main client was Louis XIV and it is known that he sold to
the King a very large blue diamond known as the French Blue which is thought to
have yielded the Hope; it is here that the history of blue diamonds began. These
Indian deposits have now been worked out and so nearly all the blue diamonds
that now appear on the market come from the Premier Mine near Pretoria in South
Africa.
Natural blue diamonds are among the rarest of colored
diamonds and their color comes from the presence of minute amounts of the
element boron incorporated within the crystal lattice of the stone during its
crystallization process. They belong to the extremely rare Type IIB category of
diamonds and are semi-conductors of electricity; an attribute which makes them
unique amongst other diamonds.
The pear-shaped diamond of 12.02 carats offered here is part
of a very elite group of remarkable blue diamonds offered at auction and has
been awarded the highest color grade of VIVID by the GIA. Furthermore it is to
date the largest vivid blue diamond to appear at auction making it a highly rare
and collectible gem."
The stone did not sell. Christies was predicting it to go for
between $5 and $6 million U.S. dollars. I contacted Christies.com and asked them
about the stone, they told me that the owner does not plan to put it back up for
auction in the foreseeable future. 
The Blue Magic out of its 18K white gold ring setting. The gem measures 21.42 ×
11.61 × 7.76 mm.