Diamond damage is ubiquitous among producers of larger high-value gem diamonds. Furthermore, the Letšeng mine has a unique diamond distribution with a significant portion of its revenue held in the +5mm fraction (greater than two carats).

The Group has been working to mitigate the impact of diamond damage on Letšeng’s production for many years. While incremental improvements have been achieved through optimising operating practices and various technological enhancements, tweaking conventional technology will not realise the step changes required to significantly reduce diamond damage.

The potential changes for significantly improving revenue through reducing diamond damage are:

  • the early identification of liberated diamonds;
  • identification of diamonds within kimberlite; and
  • a non-mechanical means of liberating these diamonds within kimberlite.

Gem Diamonds has made significant progress on the identification, validation and testing of technologies from various industries to complement its innovation drive of early detection and non-mechanical means of liberating diamonds.


Gem Diamonds successfully validated the detection of diamonds within kimberlite using scanning technology in conjunction with proprietary imaging and sorting algorithms. Two types of technologies are under investigation with varying degrees of detection potential, scalability and investment required. The proof of concept plant construction at Letšeng has highlighted various impediments and opportunities that need to be addressed and considered to enhance the operation of the technology employed.


Once a diamond has been identified within the kimberlite, the next step is to liberate this diamond without causing any damage. A non-mechanical liberation unit was developed inhouse, that utilises high voltage pulse power for the selective fragmentation of composite materials, as a means of liberating the encapsulated diamonds. Testing of this unit at Letšeng mine commenced in the beginning of 2018, at altitude, with substantial progress made throughout the year.

Process of liberating diamonds within kimberlite using innovative technology


Kimberlite rock to be scanned using scanning technology.


Scan results detecting diamond within kimberlite.


Electrical power utilised to break kimberlite and liberate diamond.


Rough 0.91 carat diamond exposed.