[1] Unusual for Africa, and due to the elevation, temperatures at the mine drop to -20 °C, and snowfalls are common in winter.

This means that Letšeng has a chilly climate with fairly cool temperatures throughout the year, even for Lesotho, and snowfalls can happen as well.

In terms of precipitation April and October serve as transitions between the wet and dry seasons.

Previously the largest diamond found at Letšeng was the 120.2 grams (601 carats) Lesotho Brown, recovered in 1967.

It is a type II D colour, with potential to yield a 30 grams (150 carats) cut stone.

Chief executive Clifford Elphick said: "Preliminary examination of this remarkable diamond indicates it will yield a record-breaking polished stone of the very best colour and clarity, and has no inclusions visible in its rough form.