Rare and Immense Colorless Jeremejevite--A World-Class Gem for the Knowledgable Collector, Ilakaka, Madagascar. Photo Bonhams

Jeremejevite is often mentioned as being the rarest of all rare gemstones.
Most frequently seen as tiny, bluish, elongated, narrow crystals of just a few millimeters in length they were first found in Namibia, the only known source for the mineral until just a few years ago.
In 2004, a discovery of larger gems was made in Ilakaka, Madagascar at the famous placer deposit which has produced and still produces fantastic fancy colored sapphires.
One of the first large jeremejevites found, a 59.58 carats example, was illustrated in the Tucson Report of Gems & Gemology, (see G&G Vol 44 N°1, Spring 2008, pp74-75). Although, larger than the present example on offer, that stone displayed many brownish needles whereas the present stone is flawless.
If this stone were a diamond it would certainly be graded as "E" color and, it is interesting to note, that its optical and physical properties resemble those of topaz while the original crystal shape resembles that of beryl.
It is very unusual to encounter such a rare gem with such a combination of exceptional clarity and size, good polish, and excellent proportions.
A world-class example, this cushion-cut gem with its modified brilliant-cut crown and step-cut pavilion, is a fantastically transparent stone which is near colorless.

Weighing approximately 38.08 carats and measuring 20.07 x 17.97 x 13.60mm. Sold for US$ 43,750 (€32,700)

Accompanied by a Gemological Institute of America Identification report 17551924 dated July 11, 2008 identifying the stone as a Jeremejevite.

Bonhams. Gems, Minerals and Lapidary Works of Art New York - 23 May 2012