Lucapa Diamond Company has recovered more large diamonds from the Lulo diamond mine in Angola.
The latest stones include diamonds weighing 103 carats and 83 carats, both recovered from Mining Block 8.
"The 103-carat light brown diamond and 83-carat Type IIa diamond continue to evidence the special nature and potential of the Lulo resource," the miner said.
De Beers sold rough diamonds with a provisional value of $450 million in the 10th sales cycle (Global Sightholder Sales and Auction Sales) of 2017.
The mining giant said that there had been a continuation of good demand heading towards the end of the year.
The UN Office in the Russian Federation has ranked ALROSA in the top three firms for environmental responsibility among Russian mining and smelting companies.
De Beers sold a provisional $418 million of rough stones at its tenth and final sales cycle of 2016.
De Beers said the confirmed value of goods for its previous sales cycle was $476 million, compared with a provisional figure of $470 million stated just after the sale.
In December 2016, sales came to $248 million.
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".
Rio Tinto has reduced its mineral resources estimate for the Argyle diamond mine in Western Australia.
The miner said in a statement that estimated mineral resources - the volume of material that can be extracted for economic purposes - fell last year.
The miner cut its estimate by 66 percent to 15 million tonnes in 2016.
Russian diamond mining giant Alrosa has appointed Sergey Ivanov Jr as chief executive.
Just 36-years-old, he replaces Andrey Zharkov who is leaving the post early. Zharkov has been at odds with officials over Alrosa's 2017 budget.
I. Hennig Tenders will hold three rough diamond tenders at the Israel Diamond Exchange (IDE) International Tender Center from March 13-16.
De Beers Group has announced a research project to deliver carbon-neutral mining at some of the company’s operations in as few as five years.
Members of ALROSA Supervisory Board voted to approve Anton Siluanov, Minister of Finance of the Russian Federation, as Chairman of the Supervisory Board.
Yegor Borisov, Head of the Republic of Sakha (Yakutia), was elected as First Deputy Chairman of the Supervisory Board. Alexander Galushka, Minister for the Development of the Russian Far East, remains as Deputy Chairman of the Supervisory Board.