Lucapa and its partners, Empresa Nacional de Diamantes and Rosas & Petalas, said the sale of the alluvial diamonds recovered from mining blocks four and six generated an average price of $1,150 per carat.
The sale took the gross sales proceeds from Lulo so far this year to $15.9 million at an average price of $1,642/ct.
The sale excluded a number of large white specials stones and a coloured special recovered which were being held for a future sale.
Lucapa's shares were 1.85% lower Monday at A27c (US20c).