BlueRock Diamonds produced 2,438 carats in the first half of the year at its Kareevlei diamond mine, in South Africa compared with 543 carats, a year earlier.
Company chief executive Adam Waugh said 34,247 tonnes were processed during the second quarter with year-on-year H1 2018 production up 81 percent to 73,028 tonnes from last year’s 40,343 tonnes.
"Thanks to our experienced team on the ground, we have had a successful quarter, continuing to produce exceptional quality diamonds from our Kareevlei project, despite five weeks of downtime due to bad weather and a fault in our crushing circuit,” he said.
Meanwhile, BlueRock sold 875.31 carats in the second quarter, compared with 1,563 carats in the first quarter, at average revenue of $305.34 per carat.
Mining commenced at the company's second kimberlite pipe, KV1 in June 2018.
The pipe has an inferred grade of 6.3cpht and was anticipated to provide material contribution this year.