Unlocking Mystery of Huge Pink and White Diamond
October 20, 25
(IDEX Online) - Experts at GIA in Gaborone, Botswana, may have unlocked the mystery of a remarkable 37.41-carat diamond that is part pink, part colorless.
They believe the larger pink section was itself originally colorless, and became pink as a result of significant stress that changes the diamond's crystal structure (known as plastic deformation). The smaller colorless section is believed to have been formed later.
"The pink section likely was initially colorless and then plastically deformed, perhaps by a mountain-forming event millions of years ago, resulting in its pink color, with the colorless section forming at a later time," says Dr. Sally Eaton-Magana, senior manager of diamond identification at GIA in Carlsbad, California, USA.
The exceptionally rare Type IIa bicolor stone was recovered by Lucara in August at its Karowe mine.
It measures 24.3mm �- 16.0mm �- 14.5 mm, with a mostly sharp boundary between the pink and colorless zones, according to a GIA article to be published in the next print issue of its Gems & Gemology journal.
GIA says it has previously examined comparable type Ia pink and colorless bicolor rough stones, both reportedly from Australia. They were both less than 2 carats.
Soon after the diamond was recovered, manufacturer HB Antwerp, which has an agreement to cut and polish Lucara's more valuable diamonds, said: "This stone has the potential to become one of the most important pink diamonds ever polished."
Main pic by Wanling Tan shows a 4mm field of view. Inset pic by Tebogo Hambira shows the whole stone.