Lucapa Diamond Company's second diamond sale of 2017 raised gross sales of $6.9 million.
The mining firm said that the average price per carat for the parcel of 1,552 carats of alluvial diamonds from the Lulo diamond project in Angola was $4,446, adding that this emphasised "the quality of the diamond recoveries and the continued strength in the market for large, high-quality diamonds".
"This brings the total gross proceeds achieved at Lulo to date in calendar 2017 to US$10.7 million."
The lot of stones included the 227-carat Type IIa D color stone found last month.
The forthcoming diamond sale will include diamonds weighing 62 carats, 65 carats and 25 carats.